Can you get medical cannabis for ulcerative colitis or IBD in the UK?

Ulcerative colitis and Crohn's disease are assessed by UK private specialists, and the trials here have produced an unusually clear and unusually important finding: symptoms improve while the inflammation does not. That distinction is the whole point of this page.

Is inflammatory bowel disease treated with medical cannabis in the UK?

IBD is assessed by private specialists, for symptoms that persist despite the disease being treated. It is not an NHS treatment, nothing is licensed for it, and it is not a treatment for the inflammation itself.

Crohn's disease and ulcerative colitis are managed by gastroenterology using aminosalicylates, corticosteroids, immunomodulators such as azathioprine, biologics and, where needed, surgery — with the goal of controlling inflammation and preventing complications. Symptom relief matters, but it is not the same objective, and the two can come apart.

This guide covers inflammatory bowel disease as a whole, and ulcerative colitis in particular. Crohn's disease has its own guide, which goes further into the Cochrane review and the trials specific to it: Can you get medical cannabis for Crohn's disease?

In IBD, feeling better while inflammation continues is a specific and serious risk. Untreated inflammation causes strictures, fistulas, bowel damage and increased cancer risk over time. Symptom relief that masks that is harmful, which is why continued gastroenterology review and monitoring is non-negotiable.

What the evidence actually shows

IBD is the clearest example in this whole field of a treatment improving how people feel without improving the disease. Both randomised trials point the same way.

An early placebo-controlled study in Crohn's disease found that smoked cannabis improved Crohn's Disease Activity Index scores, with clinical remission in a minority — but no improvement in inflammatory markers, and the trial did not meet its primary endpoint. A later randomised controlled trial published in the Journal of Crohn's and Colitis gave 56 patients CBD-rich cannabis oil or placebo for eight weeks: the cannabis group had greater symptom score reduction and better quality of life, while endoscopic scores and inflammatory markers were unchanged. The title says it directly — clinical but not endoscopic response.

UK Medical Cannabis Registry data in 116 IBD patients reports improvements in IBD-specific quality of life, anxiety, sleep and general health measures over 18 months, with the usual observational caveat. None of this is evidence of an anti-inflammatory effect in people. Registry data of this kind records what happened to people who chose and stayed on treatment; it has no placebo group and no way of separating a real effect from the natural ups and downs of the condition, from other changes to care, or from the well-known tendency of symptoms to improve when someone starts a treatment they believe in. It is useful for describing experience and generating hypotheses, and it is not the same thing as proof.

What a specialist will want to see

There is no UK list of qualifying conditions, so nothing here entitles you to a prescription. A specialist works through your history and decides whether a monitored trial is justified for you. For inflammatory bowel disease they will typically look at:

• Whether you have Crohn's disease or ulcerative colitis, and how active it currently is
• Your current IBD treatment and whether disease control is actually adequate
• Recent inflammatory markers, faecal calprotectin and endoscopy findings
• Which symptoms persist despite good disease control — pain, urgency, appetite, fatigue, sleep
• Whether you have had surgery, strictures or fistulas, which change the risk picture
• That your gastroenterology team knows and continues to monitor you

The general requirements — age, a documented diagnosis, the convention that two standard treatments have been tried, and access to your medical records — are covered in What are the requirements?

Risks and reasons a specialist may say no

The headline risk in IBD is masking. If pain and urgency improve while inflammation continues unchecked, damage accumulates silently — and the improvement itself can reduce the urgency of follow-up.

There are practical risks too. Cannabis can slow gut motility, which is unhelpful where strictures are present. Malnutrition and weight loss are common in active IBD, and appetite effects cut in both directions. Regular use has been associated in some observational studies with an increased likelihood of surgery in Crohn's disease, which may reflect symptom masking rather than a direct effect. The general cautions — drowsiness, driving impairment, psychosis history, pregnancy — apply as elsewhere.

How medical cannabis is thought to help

The mechanism in inflammatory bowel disease is not settled, and the trials caution against overstating it. The general framework is that the body has an endocannabinoid system — receptors and signalling molecules found throughout the nervous system and the gut wall — that is involved in pain, gut motility, appetite and immune signalling, and the cannabinoids in cannabis act on that system.

THC and CBD interact with it in different ways, which is why products are described by their balance of the two rather than as a single drug. Cannabinoid receptors are present in the gut lining and the nerves that supply it, which is a plausible route by which pain, cramping and urgency might ease. The important point, and the recurring theme of this page, is that any effect demonstrated so far has been on symptoms rather than on the inflammation driving the disease. For the underlying biology, see the endocannabinoid system explained and THC and CBD explained.

What treatment involves in practice

Where a specialist judges a supervised trial reasonable, the approach is consistent: start at a low dose, increase slowly, and review honestly. The starting dose is deliberately cautious, and changes are guided by your response and by any side effects rather than by a fixed schedule.

The usual formats are oils or capsules by mouth and dried flower for vaporising. Oils are steady and simple to measure; vaporised flower acts faster but its effect is shorter. Your specialist decides the format and the cannabinoid balance with you — there is no dose that suits everyone. How a dose is set and adjusted is covered in how a dose is decided and adjusted, and the formats in how cannabis-based medicines are taken.

Follow-up is central. Reviews check whether symptoms have genuinely improved and whether side effects are tolerable, while your gastroenterology team keeps monitoring the disease itself with the usual markers and endoscopy. If it is not helping enough, it is stopped. How soon any effect appears varies from person to person — see how long cannabis medicines take to work — and the common unwanted effects are set out in side effects of cannabis-based medicines.

Living with treatment day to day

A prescription brings some practical responsibilities that are easier to manage if you understand them from the start, particularly around driving, work and travel.

• Driving. THC-containing products can impair driving, and you must never drive while impaired; a medical defence applies when a prescribed medicine is taken as directed. See driving with a medical cannabis prescription.
• Work and testing. A workplace test can detect THC, so it is worth knowing your position in advance: medical cannabis, drug testing and work.
• Travel. Carrying a prescribed cannabis-based medicine abroad depends on the destination country's law: travelling abroad with a prescription.
• Your GP. Telling your GP keeps your record complete and your care joined up: telling your GP.

If you want to take this further

The useful next step is a proper assessment, not a better list. Gather your diagnosis, the treatments you have already tried and what happened with each, and your current medicines — that is what a specialist needs in order to give you a straight answer.

The consultation itself, and what happens after it, is set out in What is the process to get a medical cannabis prescription? If inflammatory bowel disease is not the only thing you are being treated for, say so early: other conditions and other medicines change the assessment.

Patient guide · Written by the Flora House editorial team · Last reviewed: 7 October 2026