IBS and the GI-MAP Stool Test

Educational overview · Medically reviewed by Madison Ordway, FDN-P

Irritable bowel syndrome (IBS) is a common disorder of gut-brain interaction that causes abdominal pain with altered bowel habits. It is a clinical diagnosis made by a physician — the GI-MAP (Gastrointestinal Microbial Assay Plus) does not diagnose IBS. What a comprehensive stool test can do is help a practitioner look under the hood: at the microbiome, at possible pathogens, and at markers that help rule inflammatory disease in or out.

What the microbiome research shows in IBS

A systematic review of gut-microbiota studies in IBS found that people with IBS tend to have a microbiota that differs from healthy controls, supporting a microbial contribution to the condition (PMID: 30940523). A comprehensive stool test profiles many of these organisms at once, which is why practitioners use it when building an IBS work-up.

Ruling inflammatory disease in or out

Because IBS and inflammatory bowel disease can produce overlapping symptoms, distinguishing them matters. Faecal calprotectin — an intestinal-health marker on the GI-MAP — helps make that distinction, reliably separating IBD from IBS in adults in meta-analysis (PMID: 20634346). A normal calprotectin makes active IBD less likely; an elevated one prompts further evaluation.

The GI-MAP is one input a practitioner uses alongside your history and, where appropriate, other tests. It does not replace clinical evaluation.

Related: All conditions · Calprotectin · SIBO · GI-MAP overview