Differentials

Common

Gastritis

History

use of non-steroidal anti-inflammatory drugs; burning epigastric pain often relieved by food; may be aggravated by recent stress or anxiety

Exam

tenderness to palpation in the epigastrium or normal examination

1st investigation
  • Helicobacter pylori urea breath test:

    positive

    More
  • Helicobacter pylori faecal antigen test:

    positive

    More
Other investigations
  • upper gastrointestinal endoscopy:

    gastritis; antral mucosal biopsies may reveal H pylori infection, which requires antibiotic therapy; may confirm aetiology such as eosinophilic gastritis

    More

Gastro-oesophageal reflux disease

History

typical: heartburn and regurgitation; atypical: minimal epigastric burning or regurgitation; nausea predominates; morning nausea common

Exam

tenderness in the epigastrium on palpation or normal examination

1st investigation
  • proton-pump inhibitor (PPI) trial:

    symptom improvement

    More
Other investigations
  • upper gastrointestinal endoscopy:

    may be normal or reveal oesophageal inflammation ranging from erythema to frank ulceration

    More
  • ambulatory pH monitoring:

    confirms acid reflux if endoscopy normal; pH >4 more than 4% of the time is abnormal

    More

Peptic ulcer disease

History

use of non-steroidal anti-inflammatory drugs; burning epigastric pain often relieved by food

Exam

tenderness to palpation in the epigastrium or normal examination

1st investigation
  • Helicobacter pylori urea breath test:

    positive

    More
Other investigations
  • upper gastrointestinal endoscopy:

    reveals gastritis, gastric ulcer, duodenal ulcer, or duodenitis; antral mucosal biopsies reveal H pylori infection, which requires antibiotic therapy

    More

Viral gastroenteritis

History

diarrhoea; abdominal pain; low-grade fever in viral disease; high-grade fever with toxicity in bacterial aetiology

Exam

diffuse abdominal tenderness to palpation; signs of volume depletion (altered mental status, poor skin turgor, dry mucous membranes, sunken eyes, irritability, and hypotension)

1st investigation
  • clinical diagnosis:

    diagnosis based on patient history and examination

    More
Other investigations
  • serum electrolytes:

    may reveal low sodium and potassium; urea may be elevated

    More
  • stool culture:

    may identify microbial agent; usually unrevealing

    More

Food poisoning

History

diarrhoea, abdominal pain; symptoms develop within several hours to days following meal; symptoms may improve or persist for weeks leading to chronic disease

Exam

epigastric tenderness; lower abdominal tenderness to palpation; signs of volume depletion (altered mental status, poor skin turgor, dry mucous membranes, sunken eyes, irritability, and hypotension)

1st investigation
  • serum electrolytes:

    may reveal hypokalaemic metabolic acidosis secondary to diarrhoea; hyper- or hyponatraemia and elevated urea secondary to dehydration

    More
  • stool microscopy:

    red and white blood cells present/positive in invasive or inflammatory diarrhoea; may detect specific ova and/or parasite

  • stool culture:

    isolation of specific pathogen

Other investigations
  • stool polymerase chain reaction:

    positive for organism

Chronic post-viral nausea and vomiting

History

symptoms become chronic after acute viral or bacterial gastroenteritis

Exam

epigastric tenderness; signs of volume depletion (altered mental status, poor skin turgor, dry mucous membranes, sunken eyes, irritability, and hypotension)

1st investigation
  • upper gastrointestinal endoscopy:

    normal

Other investigations
  • solid meal gastric emptying study:

    gastroparesis

  • gastric electrical activity:

    may show abnormalities of frequency, amplitude, and/or propagation

Migraine

History

recurrent nausea and/or vomiting in the presence of headache and disturbed vision

Exam

no neurological findings but abdomen may be tender due to vomiting/retching

1st investigation
  • no initial test:

    clinical diagnosis

Other investigations
  • CT head:

    normal in migraine; exclude alternate diagnosis

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  • MRI head:

    normal in migraine; exclude alternate diagnosis

    More

Motion sickness

History

precipitating event (e.g., car, aeroplane, or boat ride)

Exam

normal

1st investigation
  • clinical diagnosis:

    diagnosis based on patient history with a normal examination.

Other investigations
  • autonomic nervous system tests:

    may provoke the symptoms

Benign paroxysmal positional vertigo

History

brief, sudden, episodic vertigo

Exam

normal neurological exam

1st investigation
  • Dix-Hallpike manoeuvre:

    positive

  • supine lateral head turns:

    positive

    More
Other investigations
  • audiogram:

    normal in primary BPPV, unless co-existing condition present; can be abnormal in secondary BPPV

Stroke (embolic/ischaemic/haemorrhagic)

History

transient nausea, loss of vision, instability, dizziness

Exam

focal neurological deficits

1st investigation
  • CT head:

    oedema or infarct in brain

Other investigations

    Hypercalcaemia

    History

    alterations of mental status, abdominal pain, constipation, muscle pains, polyuria, headache

    Exam

    normal

    1st investigation
    • calcium:

      elevated; >2.63 mmol/L (>10.5 mg/dL)

    • parathyroid hormone:

      suppressed (non-hyperparathyroid diagnoses such as malignancy) or elevated (hyperparathyroidism)

    Other investigations

      Hypothyroidism

      History

      fatigue; cold intolerance; dyspepsia

      Exam

      hair loss; dry skin; delayed reflexes; goitre

      1st investigation
      • thyroid-stimulating hormone (TSH):

        elevated in primary hypothyroidism

        More
      Other investigations
      • T4 (serum free thyroxine):

        low or normal

        More

      Gastric outlet obstruction

      History

      history of peptic ulcer disease; vomitus is yellow gastric juice or may contain blood; upper abdominal pain is prominent

      Exam

      epigastric tenderness and/or distension; a rigid abdomen with rebound tenderness suggests concurrent bowel perforation and acute peritonitis

      1st investigation
      • upper gastrointestinal series:

        gastric distension

      • upper gastrointestinal endoscopy:

        reveals the site and cause of obstruction

        More
      Other investigations
      • CT abdomen:

        reveals the site of obstruction or free air under the diaphragm indicating perforation

        More
      • MRI abdomen:

        reveals the site of obstruction or free air under the diaphragm indicating perforation

        More

      Small bowel obstruction

      History

      bilious vomiting; peri-umbilical location of pain

      Exam

      peri-umbilical tenderness; abdominal distension; bowel sounds high pitched or absent; rigid abdomen with rebound tenderness suggests concurrent bowel perforation and acute peritonitis

      1st investigation
      • CT abdomen:

        reveals site of obstruction or free air under the diaphragm indicating perforation

        More
      Other investigations
      • MRI abdomen:

        reveals the site of obstruction or free air under the diaphragm indicating perforation

        More

      Large bowel obstruction

      History

      lower abdominal pain with or without distension; faeculent vomitus

      Exam

      tenderness and/or distension in lower abdomen; bowel sounds may be absent; a rigid abdomen with rebound tenderness suggests concurrent bowel perforation and acute peritonitis

      1st investigation
      • CT abdomen:

        reveals site of colonic obstruction; free air under the diaphragm indicating perforation

        More
      Other investigations
      • colonoscopy:

        may reveal mucosal lesion that may narrow the bowel lumen

      Choledocholithiasis

      History

      right upper quadrant (RUQ) or epigastric pain, postprandial symptoms

      Exam

      RUQ tenderness; may have jaundice

      1st investigation
      • abdominal ultrasound:

        stones in bile duct

      • LFTs:

        elevated alkaline phosphatase; elevated bilirubin

      Other investigations
      • magnetic resonance cholangiopancreatography (MRCP):

        stones in bile duct

      Acute cholecystitis

      History

      history of prior biliary colic; right upper quadrant (RUQ) pain; may have fever or referred right shoulder pain

      Exam

      may have positive Murphy sign (right subcostal tenderness, worse after deep inspiration); may have tender RUQ mass; possible jaundice

      1st investigation
      • CBC:

        elevated WBC count

      • LFTs:

        may reveal elevated bilirubin, alkaline phosphatase, alanine aminotransferase, and gamma glutamyl transferase

      • ultrasound RUQ:

        may show thickened gallbladder wall with calculi or pericholecystic fluid collection

      Other investigations
      • CT or MRI of the abdomen:

        may show irregular thickening of the gallbladder wall; poor contrast enhancement of the gallbladder wall (interrupted rim sign); increased density of fatty tissue around the gallbladder; gas in the gallbladder lumen or wall; peri‐gallbladder abscess

        More

      Post-gastrointestinal surgery

      History

      previous surgery (fundoplication, oesophagectomy, gastrojejunostomy [Bilroth I or II], or bariatric operation); epigastric discomfort; bloating; regurgitation after oesophagectomy with early satiety

      Exam

      epigastric tenderness; tender scars, positive Carnett's sign (occurs when a combination of pressure on the scar and flexion of the head clearly exacerbates the patient's typical pain)

      1st investigation
      • upper endoscopy:

        mechanical obstruction at site of surgery, mucosal abnormalities, or normal

      Other investigations
      • gastric emptying study:

        gastroparesis or disordered gastric emptying

      • gastric electrical activity:

        may show abnormalities of frequency, amplitude, and/or propagation

      Severe constipation

      History

      constipation; altered bowel habits; abdominal pain; pain on defecation

      Exam

      tender abdomen; palpable abdominal mass

      1st investigation
      • acute abdominal series:

        dilated loops of bowel; faecal loading in right colon

      Other investigations
      • anorectal manometry:

        dyssynergia, impaired/absent recto-anal inhibitory reflex, abnormal rectal sensation (hypo- or hypersensitivity)

      • transit studies:

        retention of >20% of radio-opaque markers on an abdominal x-ray performed 120 hours after ingestion of the capsule indicates slow colonic transit; retention of a wireless motility capsule for >59 hours after capsule ingestion also provides an accurate assessment of colonic transit time

      • barium defecography:

        incomplete evacuation of the rectum, poor rectal stripping wave, abnormal perineal descent

      Irritable bowel syndrome (IBS)

      History

      altered bowel habits (alternating constipation and diarrhoea), bloating, abdominal pain and distension, stress-related symptoms

      Exam

      normal in most patients; abdominal tenderness in some cases

      1st investigation
      • no initial test:

        diagnosis of exclusion

      Other investigations
      • faecal calprotectin:

        <50 micrograms/g makes inflammatory bowel disease unlikely (and IBS more likely)

      • colonoscopy:

        may demonstrate alternate diagnosis such as inflammatory bowel disease or neoplasm

        More

      Cyclic vomiting syndrome (CVS)

      History

      onset in childhood; migraine common; symptom-free weeks

      Exam

      normal

      1st investigation
      • no initial test:

        clinical diagnosis

        More
      Other investigations
      • gastric electrical activity:

        may show abnormalities of frequency, amplitude, and/or propagation

      • endoscopy:

        normal

      • solid meal gastric emptying study:

        normal

        More

      Gastric dysrhythmias

      History

      nausea, early satiety, fullness worse after meals

      Exam

      normal

      1st investigation
      • gastric electrical activity:

        may show abnormalities of frequency, amplitude, and/or propagation

      Other investigations
      • endoscopy:

        normal

        More
      • gastric emptying study:

        normal

        More

      Gastroparesis

      History

      nausea, early satiety, fullness, and vomiting of undigested food; all symptoms are worse after ingestion of meals; history of diabetes or Parkinson's disease

      Exam

      succussion "splash" rarely detected; weight loss, orthostatic hypotension

      1st investigation
      • solid meal gastric emptying study:

        >60% after 2 hours or >10% after 4 hours after consumption of the meal

      • wireless motility capsule (WMC):

        gastric emptying time >5 hours

        More
      Other investigations
      • gastric electrical activity:

        may show abnormalities of frequency, amplitude, and/or propagation

      • endoscopy:

        no evidence of mucosal inflammation

      Bacterial peritonitis

      History

      abdominal pain; nausea or vomiting ranges from mild to severe; fever low grade to severe; recent abdominal surgery

      Exam

      rigid abdomen with rebound tenderness

      1st investigation
      • diagnostic paracentesis with ascitic fluid analysis:

        appearance: 'hazy', 'cloudy', 'bloody'; absolute neutrophil count >250 cells/mm³; culture: growth of causative organism

        More
      Other investigations
      • CT abdomen:

        air under diaphragm, ascites; thickened bowel wall, intra-abdominal fluid or masses

      Anorexia nervosa

      History

      abnormalities in body image, depression, amenorrhoea, or psychosocial dysfunction

      Exam

      cachexia; signs of volume depletion (altered mental status, poor skin turgor, dry mucous membranes, sunken eyes, irritability, and hypotension), signs of malnutrition (loss of subcutaneous fat, apathy and lethargy, pallor, depigmentation, enlarged abdomen, winged scapula, flaky skin, bipedal oedema)

      1st investigation
      • clinical diagnosis:

        Meets clinical criteria for anorexia nervosa (e.g., DSM-5-TR)

      • solid meal gastric emptying study:

        gastroparesis

      Other investigations
      • gastric electrical activity:

        may show abnormalities of frequency, amplitude, and/or propagation

      Bulimia nervosa

      History

      abnormalities in body image, depression, other psychosocial dysfunction

      Exam

      normal examination; possible signs of volume depletion (altered mental status, poor skin turgor, dry mucous membranes, sunken eyes, irritability, and hypotension) and malnutrition (loss of subcutaneous fat, apathy and lethargy, pallor, depigmentation, enlarged abdomen, winged scapula, flaky skin, bipedal oedema); may have teeth enamel erosion from repeated vomiting

      1st investigation
      • clinical diagnosis:

        Meets clinical criteria for bulimia nervosa (e.g., DSM-5-TR)

      • solid meal gastric emptying study:

        normal

      • serum electrolytes:

        may show hypokalaemia or alkalosis

        More
      Other investigations
      • gastric electrical activity:

        may show abnormalities of frequency, amplitude, and/or propagation

      Pregnancy

      History

      sexually active; missed period; morning nausea

      Exam

      pelvic examination may reveal gravid uterus or pelvic masses that suggest an alternate diagnosis; may have signs of volume depletion in hyperemesis gravidarum

      1st investigation
      • urine or blood tests for pregnancy:

        positive

      • ultrasound pelvis:

        confirms pregnancy, rules out ectopic pregnancy, molar pregnancy, or any other structural abnormalities that suggest pelvic inflammatory disease (e.g., tubo-ovarian abscess)

      Other investigations
      • thyroid function tests:

        may show suppressed thyroid-stimulating hormone in hyperemesis gravidarum

      Drug-induced

      History

      symptoms not related to eating or bowel movements; onset days to weeks after starting the medicine; symptoms recur 3 to 4 days after re-initiation of medicine (e.g., chemotherapy agents); causative drugs include non-steroidal anti-inflammatory drugs (NSAIDs), antidepressants, anti-arrhythmics, opioids, chemotherapy, oestrogen/progesterone, theophylline, digoxin, lubiprostone, metformin, exenatide

      Exam

      epigastric tenderness may be present with NSAIDs

      1st investigation
      • therapeutic trial:

        nausea resolves on cessation of medicine

        More
      Other investigations

        Nephrolithiasis

        History

        flank pain, may radiate to groin; dysuria

        Exam

        costovertebral angle tenderness

        1st investigation
        • urinalysis:

          microscopic or gross haematuria

        • noncontrast CT abdomen:

          size and location of stones

        Other investigations

          Uraemia

          History

          existing renal disease or diabetes; fatigue, anorexia, weight loss; severe cases may have muscle cramps, pruritus, mental and visual disturbances; increased thirst

          Exam

          oedema; sallow skin; pallor; occult gastrointestinal bleed; hypertension

          1st investigation
          • 24-hour urine creatinine clearance:

            <10 to 20 mL/minute

            More
          • renal profile:

            hyperkalaemia; acidosis; hypocalcaemia; hyperphosphataemia

          • ultrasound kidneys:

            large kidneys in hydronephrosis, obstructions; small kidneys in chronic irreversible damage

          Other investigations
          • CT abdomen:

            size and morphology of the kidneys, lymph nodes

          Idiopathic functional dyspepsia or post-prandial distress syndrome

          History

          vague epigastric discomfort, early satiety, and prolonged fullness

          Exam

          normal

          1st investigation
          • no initial test:

            diagnosis of exclusion

          Other investigations
          • upper gastrointestinal endoscopy:

            excludes structural lesions or inflammation

          Uncommon

          Acute coronary syndrome

          History

          may have cardiac risk factors such as hypertension or diabetes; may have previous myocardial infarction or stable angina; chest pain; diaphoresis; dyspnoea

          Exam

          may have hypotension or hypertension; may have rales, oedema, or abnormal heart sounds

          1st investigation
          • ECG:

            ST-T wave changes, ischaemic changes, or dysrhythmia

          • troponin levels:

            elevated

          Other investigations

            Postural orthostatic tachycardia syndrome

            History

            nausea onset with change in position (e.g., supine to upright), lightheadedness

            Exam

            usually normal; absence of dehydration

            1st investigation
            • autonomic nervous system testing:

              blood pressure and/or pulse rate do not increase in response to upright tilt, and nausea is provoked during the test

              More
            Other investigations

              Meniere's disease

              History

              vertigo, hearing loss, tinnitus, aural fullness, drop attacks

              Exam

              nystagmus, positive Romberg's test, inability to tandem walk

              1st investigation
              • audiometry:

                low-frequency, unilateral sensorineural hearing loss

              Other investigations

                Vestibular schwannoma

                History

                asymmetrical hearing loss, tinnitus

                Exam

                nystagmus, imbalance

                1st investigation
                • audiometry:

                  asymmetrical sensorineural/retrocochlear hearing loss

                • MRI head:

                  uniformly enhanced, dense mass extending into internal acoustic meatus; absence of dural tail

                Other investigations
                • CT head:

                  unilateral acoustic meatus enlargement on bone windows

                Traumatic brain injury

                History

                head trauma; headache, confusion

                Exam

                may have focal neurological deficit

                1st investigation
                • CT head:

                  may show fracture or intracranial bleed

                Other investigations
                • MRI head:

                  may show fracture or intracranial bleed

                Meningitis

                History

                headache, neck stiffness, fever, altered mental status, photophobia, seizures

                Exam

                rash, papilloedema, Kernig's or Brudzinski's sign

                1st investigation
                • lumbar puncture with cerebrospinal examination:

                  low glucose, high protein; may reveal infectious aetiology

                  More
                Other investigations
                • blood cultures:

                  may show infecting organism

                Brain abscess

                History

                headache, stiff neck, altered mental status

                Exam

                may have focal neurological deficit; Kernig's or Brudzinski's sign

                1st investigation
                • MRI head:

                  one or more ring-enhancing lesions

                Other investigations
                • blood cultures:

                  may show infecting organism

                Focal impaired awareness seizures

                History

                nausea, bizarre smells, unusual sensations or experience (rising epigastric experience, fear, deja vu, or an 'out-of-body' sensation); appearance of being in a daydream, or staring blankly

                Exam

                normal neurological examination between episodes

                1st investigation
                • EEG:

                  abnormalities in temporal lobe electrical rhythm

                Other investigations

                  Central nervous system tumours

                  History

                  unexplained headache, change in vision or motor function, poor coordination, ataxia

                  Exam

                  focal neurological abnormalities; abdominal examination is normal

                  1st investigation
                  • CT head:

                    area of hypodensity; enhancement with contrast depending on type or grade of the tumour; hyperdensity if calcification or haemorrhage present

                  Other investigations

                    Primary adrenal insufficiency (acute or chronic)

                    History

                    chronic symptoms; no abdominal pain; may have diarrhoea; may be on chronic corticosteroid medicine

                    Exam

                    normal abdominal examination; orthostatic hypotension

                    1st investigation
                    • morning serum cortisol:

                      <140 nanomols/L (<5 micrograms/dL)

                      More
                    • plasma adrenocorticotrophic hormone (ACTH):

                      >12 picomoles/L (>52 picograms/mL)

                      More
                    Other investigations
                    • ACTH stimulation test:

                      poor cortisol response to adrenocorticotropic hormone (peak <497 nanomols/L; <18 micrograms/dL)

                      More

                    Hyperthyroidism

                    History

                    heat intolerance; tremors; weight loss

                    Exam

                    tachycardia; brisk reflexes; enlarged thyroid

                    1st investigation
                    • free T4 and/or free T3:

                      elevated

                    • thyroid-stimulating hormone:

                      suppressed

                    Other investigations

                      Hypopituitarism

                      History

                      possible galactorrhoea; headache or visual field defects; weakness; dizziness; infertility; symptoms of hypothyroidism

                      Exam

                      absent axillary and pubic hair; orthostasis; reduced muscle mass; delayed return of reflexes

                      1st investigation
                      • thyroid function tests:

                        low free T4 with normal or low thyroid-stimulating hormone

                      • adrenocorticotropic hormone stimulation test:

                        inadequate cortisol response

                      • serum follicle-stimulating hormone and luteinising hormone:

                        low

                      • serum prolactin:

                        may be elevated

                      Other investigations
                      • MRI head:

                        may show pituitary tumour or sellar abnormality

                      Heat stroke

                      History

                      older age; cognitive comorbidities; use of diuretics, antihypertensives, anticholinergics, phenothiazines, tricyclic antidepressants; altered mental status

                      Exam

                      core temperatures >40°C (>104°F)

                      1st investigation
                      • serum chemistries:

                        variable abnormalities

                        More
                      • serum creatine kinase:

                        may be elevated if rhabdomyolysis

                      Other investigations

                        Acute pancreatitis

                        History

                        history of alcohol use or cholelithiasis; abdominal pain

                        Exam

                        tachycardia or orthostasis if volume-depleted; abdominal tenderness or distension

                        1st investigation
                        • serum lipase or amylase:

                          elevated (3 times the upper limit of normal)

                          More
                        Other investigations
                        • abdominal ultrasound:

                          may show pancreatic inflammation, peri-pancreatic stranding, calcifications, or fluid collections

                          More
                        • abdominal CT with oral and intravenous contrast:

                          may show diffuse or segmental enlargement of the pancreas with irregular contour and obliteration of the peri-pancreatic fat, necrosis, or pseudocysts

                          More
                        • magnetic imaging/magnetic resonance cholangiopancreatography (MRI/MRCP):

                          findings may include stones, tumours, diffuse or segmental enlargement of the pancreas with irregular contour and obliteration of the peri-pancreatic fat, necrosis, or pseudocysts

                          More

                        Diabetic ketoacidosis

                        History

                        a history of diabetes, intercurrent illness, non-adherence with insulin therapy, polyuria, polydipsia, fatigue, weight loss, nocturia, rapid deterioration in clinical state with nausea, abdominal pain, vomiting

                        Exam

                        dry mucous membranes, poor skin turgor, hypotension, and, in severe cases, shock

                        1st investigation
                        • plasma glucose:

                          elevated

                        • serum ketones:

                          elevated

                        • ABG:

                          metabolic acidosis

                        • serum electrolytes:

                          serum sodium: usually low; serum potassium: usually normal or elevated; hypomagnesaemia and hypophosphataemia may also be present

                          More
                        Other investigations

                          Bariatric surgery sequelae

                          History

                          intolerance of oral intake 3 to 6 weeks following surgery (suggests stricture); possible dysphagia

                          Exam

                          the obese abdomen may be difficult to examine; may be tachycardia, fever, and signs of respiratory distress

                          1st investigation
                          • upper gastrointestinal endoscopy:

                            demonstrates stricture

                            More
                          Other investigations
                          • gastric emptying study:

                            >60% after 2 hours or >10% after 4 hours after consumption of the meal is considered to be delayed gastric emptying

                          Primary pseudo-obstruction

                          History

                          symptoms mimic mechanical gastrointestinal obstruction; there may be a history of laparotomy with no evidence of mechanical obstruction

                          Exam

                          abdomen distended and tympanitic; bowel sounds usually absent

                          1st investigation
                          • acute abdominal series:

                            air fluid levels; dilated stomach, duodenum, colon

                          • full thickness gastrointestinal biopsy:

                            may help identify the pathophysiology of pseudo-obstruction

                          Other investigations
                          • CT abdomen:

                            dilated stomach, duodenum, small bowel, colon; no site of obstruction located

                          Secondary pseudo-obstruction

                          History

                          history of lupus, scleroderma, myotonic dystrophy or other striated muscle disorders; symptoms mimic mechanical gastrointestinal obstruction; there may be a history of laparotomy with no evidence of mechanical obstruction

                          Exam

                          abdomen distended and tympanitic; bowel sounds usually absent; sclerodactyly, malar rash

                          1st investigation
                          • antinuclear antibodies, double-stranded (ds)DNA, Smith antigen:

                            may be positive

                          • acute abdominal series:

                            air fluid levels; dilated stomach, duodenum, colon

                          Other investigations
                          • CT abdomen:

                            dilated stomach, duodenum, small bowel, colon; no site of obstruction

                          • full thickness gastrointestinal biopsy:

                            may help identify the pathophysiology of pseudo-obstruction

                          Abdominal abscess

                          History

                          abdominal pain; symptoms range from mild to severe; low-grade fever; recent abdominal surgery; night sweats; fatigue; history of cirrhosis, portal hypertension, and ascites

                          Exam

                          abdominal tenderness and/or mass; ascites and enlarged liver and spleen

                          1st investigation
                          • CT abdomen:

                            intra-abdominal abscess; ascites

                          Other investigations

                            Carcinomatous peritonitis

                            History

                            known gastrointestinal cancer; abdominal pain; symptoms range from mild to severe; low-grade fever; recent abdominal surgery

                            Exam

                            cachexia; firm abdomen; palpable abdominal mass

                            1st investigation
                            • CT abdomen:

                              ascites, thickened bowel wall, intra-abdominal fluid or masses

                            Other investigations
                            • abdominal paracentesis with biopsy:

                              histology of aspirated abdominal fluid and biopsied mass or peritoneum confirms cancer diagnosis

                            Stomach cancer

                            History

                            nausea, vomiting, and early satiety evolve slowly over weeks or months; weight loss; symptoms suggest mucosal inflammation, dyspepsia, or gastroparesis

                            Exam

                            appears ill; cachexia; epigastric tenderness

                            1st investigation
                            • upper gastrointestinal endoscopy:

                              biopsy reveals cancer

                            Other investigations
                            • CT abdomen:

                              gastric mass; enlarged lymph nodes

                            • upper gastrointestinal barium series:

                              polypoid or ulcer-like gastric mass

                            Ovarian cancer

                            History

                            nausea, vomiting, and early satiety evolve slowly over weeks or months; symptoms of dyspepsia or gastroparesis; weight loss; middle-aged woman

                            Exam

                            appears ill; cachexia; pelvic mass

                            1st investigation
                            • pelvic ultrasound:

                              presence of solid, complex, septated, multiloculated mass; high blood flow

                            • CT abdomen:

                              ovarian mass; enlarged lymph nodes

                            • CA-125:

                              may be elevated (>35 units/mL)

                              More
                            Other investigations

                              Renal cancer

                              History

                              nausea, vomiting, and early satiety evolve slowly over weeks or months; symptoms of dyspepsia or gastroparesis; unexplained weight loss, haematuria; low back pain

                              Exam

                              appears ill; cachexia; abdominal mass

                              1st investigation
                              • urinalysis:

                                gross or microscopic haematuria

                              • abdominal/pelvic ultrasound:

                                abnormal renal cyst/mass, lymphadenopathy, and/or other visceral metastatic lesions

                              • abdominal CT scan:

                                renal mass; enlarged lymph nodes

                              Other investigations

                                Small cell lung cancer

                                History

                                history of smoking; weight loss; shortness of breath; cough; haemoptysis; nausea, vomiting, and early satiety evolves slowly over weeks or months; symptoms of dyspepsia or gastroparesis

                                Exam

                                appears ill with cachexia; respiratory wheeze or decreased breath sounds

                                1st investigation
                                • CXR:

                                  central or peripheral mass, hilar lymphadenopathy, superior mediastinal lymphadenopathy, pleural effusion

                                  More
                                • CT chest:

                                  mass in the lung, massive lymphadenopathy and direct mediastinal invasion are common features; determines extent of disease

                                Other investigations
                                • biopsy:

                                  malignant cells, high nuclear to cytoplasmic ratio, nuclear fragmentation often present

                                  More

                                Pancreatic cancer

                                History

                                weight loss, anorexia, abdominal discomfort, back pain

                                Exam

                                may have jaundice or abdominal mass

                                1st investigation
                                • abdominal ultrasound:

                                  pancreatic mass, dilated bile ducts, liver metastases

                                • abdominal CT:

                                  confirms pancreatic mass and extent of spread

                                Other investigations
                                • cancer antigen (CA) 19-9 biomarker:

                                  elevated

                                  More

                                Chronic mesenteric ischaemia

                                History

                                post-prandial nausea, fullness, and early satiety; symptoms worse 30 to 60 minutes after ingestion of food; weight loss

                                Exam

                                diffuse abdominal tenderness; abdominal bruit

                                1st investigation
                                • mesenteric duplex ultrasound:

                                  confirms blood flow disturbance in the superior mesenteric artery or coeliac artery

                                • CT angiogram:

                                  confirms site of blood vessel stenosis

                                Other investigations
                                • solid meal gastric emptying study:

                                  confirms gastroparesis if present

                                • gastric electrical activity:

                                  may show abnormalities of frequency, amplitude, and/or propagation

                                Cannabinoid hyperemesis

                                History

                                age <50 years; cannabis use usually for >2 years and >once per week; may have abdominal pain; may have relief of symptoms with warm showers or baths

                                Exam

                                non-specific

                                1st investigation
                                • no initial test:

                                  diagnosis is clinical: tests may be required to rule out other causes of nausea and vomiting

                                Other investigations
                                • gastric emptying studies:

                                  may be delayed

                                  More
                                • autonomic nervous system testing:

                                  may provoke the symptoms

                                • gastric electrical activity:

                                  may show abnormalities of frequency, amplitude, and/or propagation

                                Chronic nausea and vomiting after antibiotics or anaesthetics

                                History

                                chronic symptoms develop after exposure to antibiotics or anaesthesia agents

                                Exam

                                epigastric tenderness

                                1st investigation
                                • no initial test:

                                  clinical diagnosis

                                Other investigations
                                • gastric electrical activity:

                                  may show abnormalities of frequency, amplitude, and/or propagation

                                • solid meal gastric emptying study:

                                  normal or gastroparesis

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