There are no guidelines recommending that patients with anaemia due to cobalamin or iron deficiency specifically be screened for achlorhydria.
Measurement of anti-parietal cell antibodies and gastrin-17, and the pepsinogen I to pepsinogen II ratio seem to be the most accurate tests for first-line screening of autoimmune gastropathy. Screening for anti-parietal cell antibodies alone would miss those patients who are negative for this antibody, whereas gastrin-17 levels are raised in nearly all patients with autoimmune gastropathy who have developed overt atrophy.
If the aetiology of the deficiency is unexplained, oesophagogastroduodenoscopy with biopsy of the oxyntic mucosa (fundus and corpus) could be considered to rule in or rule out atrophic gastritis as the aetiology.
Gastric atrophy and intestinal metaplasia
The American Gastroenterological Association (AGA) recommends testing for Helicobacter pylori, followed by eradication, in patients with intestinal metaplasia (IM).[67]Gupta S, Li D, El Serag HB, et al. AGA clinical practice guidelines on management of gastric intestinal metaplasia. Gastroenterology. 2020 Feb;158(3):693-702.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7340330
http://www.ncbi.nlm.nih.gov/pubmed/31816298?tool=bestpractice.com
AGA recommends against the routine use of endoscopic surveillance in patients with IM.[67]Gupta S, Li D, El Serag HB, et al. AGA clinical practice guidelines on management of gastric intestinal metaplasia. Gastroenterology. 2020 Feb;158(3):693-702.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7340330
http://www.ncbi.nlm.nih.gov/pubmed/31816298?tool=bestpractice.com
European guidelines and The British Society of Gastroenterology recommend against surveillance endoscopy in patients with gastric atrophy or gastric IM limited to the gastric antrum (in the absence of high risk factors).[120]Banks M, Graham D, Jansen M, et al. British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma. Gut. 2019 Sep;68(9):1545-75.
https://gut.bmj.com/content/68/9/1545.long
http://www.ncbi.nlm.nih.gov/pubmed/31278206?tool=bestpractice.com
[121]Dinis-Ribeiro M, Libânio D, Uchima H, et al. Management of epithelial precancerous conditions and early neoplasia of the stomach (MAPS III): European Society of Gastrointestinal Endoscopy (ESGE), European Helicobacter and Microbiota Study Group (EHMSG) and European Society of Pathology (ESP) guideline update 2025. Endoscopy. 2025 May;57(5):504-54.
https://www.thieme-connect.com/products/ejournals/html/10.1055/a-2529-5025
http://www.ncbi.nlm.nih.gov/pubmed/40112834?tool=bestpractice.com
The international Kyoto guideline recommends that patients be offered endoscopic surveillance based upon the extent and severity of atrophy.[122]Sugano K, Tack J, Kuipers EJ, et al. Kyoto global consensus report on Helicobacter pylori gastritis. Gut. 2015;64:1353-1367.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4552923
http://www.ncbi.nlm.nih.gov/pubmed/26187502?tool=bestpractice.com
Patients at high risk for gastric cancer
AGA and the American Society for Gastrointestinal Endoscopy recommend surveillance endoscopy for those with IM who are at high risk for gastric cancer due to their ethnic background, extensive IM, dysplastic IM, or family history of gastric cancer.[67]Gupta S, Li D, El Serag HB, et al. AGA clinical practice guidelines on management of gastric intestinal metaplasia. Gastroenterology. 2020 Feb;158(3):693-702.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7340330
http://www.ncbi.nlm.nih.gov/pubmed/31816298?tool=bestpractice.com
[123]ASGE Standards of Practice Committee, Evans JA, Chandrasekhara V, et al. The role of endoscopy in the management of premalignant and malignant conditions of the stomach. Gastrointest Endosc. 2015;82:1-8.
http://www.ncbi.nlm.nih.gov/pubmed/25935705?tool=bestpractice.com
The British Society of Gastroenterology recommends:[120]Banks M, Graham D, Jansen M, et al. British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma. Gut. 2019 Sep;68(9):1545-75.
https://gut.bmj.com/content/68/9/1545.long
http://www.ncbi.nlm.nih.gov/pubmed/31278206?tool=bestpractice.com
Screening endoscopy for those aged over 50 years with risk factors such as male sex, a history of smoking, pernicious anaemia, or a family history of gastric cancer