Quigley · Gastroenterology 2020 · expert review · n=?

AGA Clinical Practice Update on Small Intestinal Bacterial Overgrowth: Expert Review.

Cited 221 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Narrative expert review and clinical practice update without systematic review methodology

PubMed 32679220 · doi:10.1053/j.gastro.2020.06.090 · record verified 2026-08-27

What was done

Three authors conducted a narrative literature review to evaluate the historical background, symptomatology, pathophysiology, clinical consequences, diagnosis, and treatment of small intestinal bacterial overgrowth (SIBO). Following structured discussion, drafting, and iterative revision, the authors agreed upon nine Best Practice Advice statements for the American Gastroenterological Association.

What was found

No quantitative numerical findings or statistical measures are reported in the abstract. The authors formulated nine consensus statements establishing that SIBO lacks a precise and consistent clinical definition, symptoms traditionally include bloating, diarrhea, and abdominal pain, fecal calprotectin is unsupported for diagnosis, laboratory abnormalities can include elevated folate and vitamin B12 deficiency, understanding of normal small bowel microbiota remains limited, the role of SIBO in irritable bowel syndrome remains controversial, treatment should address underlying causes and nutritional deficiencies alongside antibiotics, and antibiotic strategies remain largely empiric.

Why it matters

This review highlights substantial diagnostic and pathophysiological uncertainties in SIBO, cautioning clinicians that current management and antibiotic strategies rely largely on empiric practice rather than robust trial data.

Limits

The update is based on expert opinion and non-systematic narrative review rather than a formal systematic review. The evidence base is constrained by undefined true prevalence, a lack of clear definitions for normal small intestinal flora, and a lack of randomized controlled trials guiding antibiotic regimens.

Cited by