Medical Cannabis for IBS and Crohn's Disease in the UK

Gastrointestinal Conditions and the Endocannabinoid System

The gastrointestinal tract is richly innervated with cannabinoid receptors. CB1 receptors are found throughout the enteric nervous system — the network of neurons that governs gut function — while CB2 receptors are present on immune cells in the gut wall. This anatomical distribution has led researchers to hypothesise that the endocannabinoid system plays a central role in regulating gut motility, visceral pain, inflammation, and the gut-brain axis.

This biological rationale underpins the growing interest in cannabis-based medicinal products for gastrointestinal conditions, including irritable bowel syndrome (IBS) and inflammatory bowel diseases (IBD) such as Crohn's disease and ulcerative colitis.

IBS: A Common and Often Undertreated Condition

Irritable bowel syndrome affects an estimated 10–20% of the UK population, making it one of the most prevalent gastrointestinal conditions. It is characterised by abdominal pain, bloating, and altered bowel habits (diarrhoea, constipation, or both), in the absence of structural abnormality. The condition is chronic, often debilitating, and poorly served by conventional treatments, many of which provide only modest symptom relief.

Emerging evidence suggests that the endocannabinoid system is dysregulated in IBS, with altered levels of endocannabinoids and cannabinoid receptor expression observed in patients. Small clinical studies and real-world registry data suggest that CBMPs may help reduce abdominal pain, bloating, and bowel urgency in IBS patients, though larger randomised controlled trials are needed.

Crohn's Disease and Ulcerative Colitis

Crohn's disease and ulcerative colitis are chronic inflammatory bowel diseases (IBD) that cause significant morbidity. Both conditions are characterised by periods of relapse and remission, with symptoms including abdominal pain, diarrhoea, rectal bleeding, fatigue, and weight loss.

Several small clinical trials have examined cannabis in Crohn's disease, with some showing improvements in clinical disease activity scores and quality of life. A 2023 Cochrane review concluded that cannabis may improve symptoms in Crohn's disease, though the evidence was of low quality and larger trials are needed. Real-world data from the UK Medical Cannabis Registry has shown improvements in pain and quality of life in patients with IBD prescribed CBMPs.

Eligibility for a Medical Cannabis Prescription for GI Conditions

IBS and IBD (Crohn's disease, ulcerative colitis) are conditions for which specialist doctors in the UK can prescribe CBMPs on a private basis. Eligibility typically requires a confirmed diagnosis and evidence that conventional treatments have not provided adequate symptom control.

How CPGUK Can Help

If you are living with IBS, Crohn's disease, or another gastrointestinal condition and have not found adequate relief through conventional treatments, CPGUK can help you understand your options. Our free patient support service can connect you with specialist clinics experienced in prescribing CBMPs for gastrointestinal conditions.