Irritable bowel syndrome and inflammatory bowel disease overlap syndrome: pieces of the puzzle are falling into place

Abstract

Irritable bowel syndrome (IBS), a common gastrointestinal disorder involving the gut-brain axis, and inflammatory bowel disease (IBD), a chronic relapsing inflammatory disorder, are both increasing in incidence and prevalence in Asia. Both have significant overlap in terms of symptoms, pathophysiology, and treatment, suggesting the possibility of IBS and IBD being a single disease entity albeit at opposite ends of the spectrum. We examined the similarities and differences in IBS and IBD, and offer new thoughts and approaches to the disease paradigm.

Keywords: Gut-brain axis; IBS-IBD overlap syndrome; Inflammatory bowel disease; Irritable bowel syndrome.

Fig. 1. Disease paradigms in IBS-IBD. Existing paradigms and our proposed one disease paradigm are shown here. These paradigms illustrate the evolution of concepts in IBS-IBD overlap syndrome. PI-IBS, postinflammatory IBS; IIBS, irritable IBS.

Fig. 2. Management consideration in IBS-IBD overlap. When considering progression or overlap of IBS-IBD, it is important to exclude undiagnosed or ongoing inflammation, and thus the need for biomarkers including fecal calprotectin (or others, either existing or in development) and pathological assessment. Triggers for ongoing inflammation are also sought especially occult infection and psychological dysfunction which are often subtle and not noticed. It is also important to assess and treat other disorders of the gut-brain axis (including visceral hypersensitivity).