Differentials

Ileus

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Less crampy abdominal pain; often associated with another cause (e.g., postoperative, systemic infection, drugs).

INVESTIGATIONS

CT scan shows passage of contrast throughout the small bowel and into the large bowel. No transition point identified.

Infectious gastroenteritis

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Vomiting, typically nonbilious.

INVESTIGATIONS

X-ray shows gas throughout abdomen; stool cultures may be positive for viruses or bacteria.

Large bowel obstruction

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Very distended abdomen; constipation progressing to absolute constipation.

INVESTIGATIONS

CT may visualize obstruction, perforation, dilatation, ischemia, malignancy.

Intestinal pseudo-obstruction

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Chronic condition; constipation; often associated with administration of neurologic drugs (e.g., amitriptyline, imipramine). Rarely, clozapine has been associated with pseudo-obstruction.[28]

INVESTIGATIONS

X-ray and CT may show dilated small or large bowel, which may be massively dilated.

Appendicitis

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Pain in right lower quadrant with nausea; vomiting (nonbilious).

INVESTIGATIONS

Ultrasound and CT may confirm diagnosis in most cases.

Pancreatitis

SIGNS / SYMPTOMS
INVESTIGATIONS
SIGNS / SYMPTOMS

Continuous upper abdominal pain radiating through to the back; nonbilious vomiting.

INVESTIGATIONS

Increased amylase and lipase; CT scan shows inflamed pancreas.

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