IBS and IBD - separate entities or on a spectrum?

Area of Science:

• Gastroenterology
• Immunology
• Microbiome Research

Background:

• Inflammatory Bowel Disease (IBD) presents with inflamed, ulcerated mucosa, distinct from Irritable Bowel Syndrome (IBS) with normal-appearing mucosa.
• However, detailed assessments reveal shared features between IBS and IBD, including immune activation, increased gut permeability, and altered gut microbiota (dysbiosis).

Purpose of the Study:

• To explore the significant overlap in pathophysiology and clinical presentation between IBS and IBD.
• To discuss the implications of evolving IBD treatments on the persistence of IBS-like symptoms in IBD patients.
• To propose future research directions for understanding the IBS-IBD continuum.

Main Methods:

• Review of current literature comparing IBS and IBD.
• Analysis of findings related to immune activation, gut permeability, and microbiota in both conditions.
• Examination of patient data from IBD cohorts in remission.

Main Results:

• IBS exhibits immune activation, increased gut permeability, altered serotonin availability, and dysbiosis, mirroring features of IBD.
• Approximately one-third of IBD patients in remission still present with persistent sensory, motility, and microbiota abnormalities.
• These persistent abnormalities in IBD patients can manifest as IBS-like symptoms.

Conclusions:

• There is a substantial overlap between IBS and IBD, challenging traditional diagnostic distinctions.
• Persistent gut abnormalities in IBD patients, even after inflammation remission, contribute to IBS-like symptoms.
• Further research is crucial to elucidate the shared mechanisms and develop targeted treatments for the IBS-IBD spectrum.