EducationHow effective is cannabis for ulcerative colitis?

How effective is cannabis for ulcerative colitis?

6 min read

Sam North

How effective is cannabis for ulcerative colitis?

Ulcerative colitis is a persistent inflammatory bowel disease (IBD) characterised by inflammation in the inner lining of the colon and rectum. This chronic condition has a diverse range of symptoms. These include diarrhoea, rectal bleeding, abdominal pain and general discomfort. The severity of these symptoms can fluctuate significantly. 


Traditionally, Ulcerative colitis has been managed through a combination of lifestyle practices and pharmaceutical medications. In recent years, medical cannabis has emerged as a potential bridge between these two options. The interest in medical cannabis as a treatment for Ulcerative colitis is mainly due to its promise in offering anti-inflammatory and analgesic (pain-relieving) properties.

Symptoms of Ulcerative colitis

Some of the most common symptoms experienced by individuals with Ulcerative colitis include diarrhoea, rectal bleeding, abdominal pain and cramping, fatigue, weight loss and loss of appetite. More severe symptoms may include joint pain, malnutrition, and anaemia.

The persistent nature of these symptoms can have a profound impact on daily life, causing discomfort, disruption, and emotional distress. Frequent and urgent trips to the bathroom can interfere with work, social activities and overall well-being. The chronic pain and cramping can further exacerbate the physical and emotional toll, leading to fatigue and decreased productivity.

How cannabis can help alleviate the symptoms of Ulcerative colitis

Research studies have indicated that cannabis may have anti-inflammatory properties that could be beneficial for individuals with Ulcerative colitis. Specifically, it could reduce inflammation in the colon and rectum. This could help alleviate many of the common symptoms of the condition, such as diarrhoea, abdominal pain and rectal bleeding.

Furthermore, cannabis may be able to influence the body's perception of pain. This means that it could provide effective relief from the discomfort and cramping experienced by individuals with Ulcerative colitis. 

The endocannabinoid system 

The endocannabinoid system regulates various physiological processes, including inflammation, pain perception and gastrointestinal function. It is composed of endocannabinoids, cannabinoid receptors CB1 and CB2 and, enzymes that break down endocannabinoids.

Cannabis is a source of phytocannabinoids (cannabinoids produced by a plant). These interact with the body’s own endocannabinoid system. In particular, they can bind themselves with the CB1 and CB2 receptors in the gut. 

This is thought to be how phytocannabinoids, CBD and THC in particular, potentially ease inflammation, reduce pain perception, and promoting healthy gastrointestinal function. This, in turn, may lead to relief from symptoms such as abdominal pain and diarrhoea.

The science of cannabis and Ulcerative colitis

Several studies have investigated the effectiveness of cannabis in treating inflammatory bowel conditions in general and Ulcerative colitis in particular. 

Basil N. Nduma et al released a review of the literature on this topic earlier this year (2023). This review highlighted that “the efficacy of cannabinoid use in IBD treatment was reported in most studies”. It also confirmed that ‘very few adverse effects were documented’.

Tim Ambrose and Alison Simmons researched the therapeutic potential of cannabis for treating inflammatory bowel disease. They found that “There is accumulating evidence that enhancing signalling through cannabinoid receptors 1 and 2 has anti-inflammatory potential in the intestine in vivo.”

A UK-based study of medical cannabis and inflammatory bowel disease also found positive results.

Tahir S. Kafil et al researched the application of medical cannabis as a treatment for Ulcerative colitis specifically (as opposed to inflammatory bowel conditions in general). The report noted that “Cannabis and some cannabinoids have been shown to decrease inflammation in animal and laboratory models, which suggests it may help people with Ulcerative colitis.” They recommended further research.

How different forms of cannabis can be administered to treat Ulcerative colitis

There are three main ways of using cannabinoids (THC and CBD) to treat Ulcerative colitis. These are inhalation, ingestion and topical application.

Inhalation: Smoking cannabis is declining in popularity due to the general risks of smoking (even without nicotine). Vaporising or vaping cannabis is, however, very popular, and offer the fast onset of effect related to inhalation without many of the health issues of smoking. Vaping delivers the cannabinoids through the respiratory system. This means that results can be experienced very quickly, in some cases almost immediately.

Oral ingestion: Tinctures can bypass the digestive system and go straight into the bloodstream through sublingual administration (under the tongue). This means that they can work almost as quickly as inhalation. Edibles have to be processed by the digestive system and hence work more slowly, and come with a much lower cannabinoid efficiency rate when compared to sublingual or inhalation administration. They can, however, provide longer-lasting relief. Both tinctures and edibles can often be taken in places where vaping (and smoking) would not be allowed.

Topical application: Topical application has limited relevance for Ulcerative colitis. It may, however, be helpful in severe cases when joint pain is an issue.

Cannabis and conventional treatment for Ulcerative colitis

Conventional treatments for Ulcerative colitis typically include medications such as anti-inflammatory drugs, immune system suppressors, and symptom-specific medications. These treatments aim to reduce inflammation, manage symptoms and promote remission. Some individuals may, however, find that conventional treatments alone are not sufficient in providing relief or managing their symptoms effectively.

Cannabis has been shown to be potentially effective in conjunction with conventional treatments for Ulcerative colitis to enhance therapeutic outcomes. It may offer additional benefits such as reducing inflammation, relieving pain, improving appetite and promoting overall well-being. By targeting different pathways in the body, cannabis may complement the effects of conventional treatments and provide a more comprehensive approach to managing the disease.

With that said, it’s important to consider the potential drawbacks of using cannabis for Ulcerative colitis. Like any medication, cannabis can have side effects. These may include drowsiness, dry mouth or changes in appetite. Additionally, cannabis has the potential to interact with prescription medications. This interaction can affect the effectiveness of the medications or lead to undesirable side effects.

Medicinal cannabis should never be seen as a ‘magic-cure’. The research suggests that it is best administered in conjunction with conventional therapeutic options.

Legal considerations

Since November 2018, specialist doctors in the UK have been allowed to prescribe cannabis-based products for medicinal purposes. This change was implemented following high-profile cases and growing evidence of the potential therapeutic benefits of cannabis for certain medical conditions.

Medical professionals will make individual assessments to decide whether to prescribe cannabis-based products. They will take into account the patient's medical history and the severity of their Ulcerative colitis. It’s important to note that simply having a diagnosis of Ulcerative colitis does not guarantee eligibility for medical cannabis treatment. Thus, medical cannabis should be viewed as only one of several treatment options available to patients.


The nature of Ulcerative colitis means that its treatment and management generally have to be adapted to reflect the fluctuations in its symptoms. The good news is that here at Releaf, we offer a highly personalised service that was created with flexibility in mind. That's why we offer tailored monthly packages based on your cannabis prescription, specialist consultations for medical cannabis, and a unique medical cannabis card for protection. 

It is important to seek medical advice before starting any new treatments. The patient advisors at Releaf are available to provide expert advice and support. Alternatively, click here to book a consultation with one of our specialist doctors.

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Sam North, a seasoned writer with over five years' experience and expertise in medicinal cannabis, brings clarity to complex concepts, focusing on education and informed use.

Our articles are written by experts and reviewed by medical professionals or compliance specialists. Adhering to stringent sourcing guidelines, we reference peer-reviewed studies and scholarly research. View our editorial policy.

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