Recent advances in the diagnosis of irritable bowel syndrome

Abstract

The symptom-based diagnosis of irritable bowel syndrome (IBS) has not been established in everyday clinical practice, and the diagnosis of this disorder remains one of exclusion. It has been demonstrated that the densities of duodenal chromogranin A, rectal peptide YY and somatostatin cells are good biomarkers for the diagnosis of sporadic IBS, and low-grade mucosal inflammation is a promising biomarker for the diagnosis of postinfectious IBS. Genetic markers are not useful as biomarkers for IBS since the potential risk genes have yet to be validated, and the intestinal microbiota cannot be used because of the lack of an association between a specific bacterial species and IBS. Furthermore, gastrointestinal dysmotility and visceral hypersensitivity tests produce results that are too nonconsistent and noncharacteristic to be used in the diagnosis of IBS. A combination of symptom-based assessment, exclusion of overlapping gastrointestinal diseases and positive biomarkers appears to be the best way to diagnose IBS.

Keywords:

• chromogranin A
• genes
• low-grade inflammation
• microbiota
• peptide YY
• somatostatin
• stem cell

Financial & competing interests disclosure

The author was supported by grants from Helse-Vest and Helse-Fonna. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript, apart from those disclosed.

Key issues

• Symptom-based diagnosis of irritable bowel syndrome (IBS) is not used in everyday clinical practice.

• Duodenal chromogranin A and rectal density of peptide YY and somatostatin cell densities appear to be good biomarkers for IBS diagnosis.

• Low-grade mucosal inflammation appears to be a good biomarker for IP-IBS.

• Genetic biomarkers cannot be considered for the diagnosis of IBS at the present time because the proposed genes have yet to be validated.

• The intestinal microbiota cannot be used in the diagnosis of IBS because the association between IBS and specific bacterial species is equivocal.

• Gastrointestinal motility tests cannot be used in the diagnosis of IBS because abnormalities of gastrointestinal motility are nonconsistent and noncharacteristic features of the disorder.

• Visceral hypersensitivity tests are not useful in the diagnosis of IBS due to discrepancies between different patient cohorts.

• A combination of symptom-based assessment, exclusion of gastrointestinal diseases that mimic IBS and intestinal endocrine cell biomarkers in combination with low-grade inflammation is proposed for the diagnosis of IBS.

Notes