Cannabis for IBS: how does medical cannabis impact IBS-related symptoms?

What are the symptoms of IBS?

IBS is a long-term condition that affects the digestive system and is considered fairly common around the world. 

In the UK specifically, IBS is thought to impact 1 in 5 people, with the condition usually first developing in people between their late teens and early 30s. But it can affect anyone of any age. 

It’s also currently incurable, with conventional treatments aimed at reducing the impact of its associated symptoms. Some of the most common IBS symptoms include:

• Stomach pain or cramps

• Abdominal pain or discomfort 

• Bloating and indigestion

• Unusual and inconsistent bowel movements, such as diarrhoea, constipation or bowel incontinence

• Nausea 

• Tiredness and fatigue

• Pelvic pain or backache

• Sleep-related issues

These symptoms can come and go over time, and may flare up for no obvious reason. But they can sometimes be triggered by certain foods and drinks, such as alcohol, caffeine, spicy or fatty food, or mental health-related issues, like stress. 

What are the conventional treatments for IBS?

Once you’ve been diagnosed with IBS, the first treatment you’re likely to be recommended by doctors involves making certain dietary and lifestyle changes.

Common advice includes eating regular meals slowly, while also making sure to not miss any meals whenever possible. 

Regular hydration is also important, but ideally the drinks you have should be water instead of fizzy drinks, alcohol or any drink containing caffeine.

Other dietary advice is often related to your specific symptoms, such as cutting down the amount of fibre you eat if you have bad diarrhoea. 

In contrast, constipation can be helped by increasing the amount of fibre you consume. Oats and linseeds can also help to reduce gassy wind and bloating.

Many doctors will also recommend you track your symptoms and note the foods you eat before you experience a flare-up. This is because there may be specific foods that trigger your symptoms, which you can then work to avoid. 

Some of the most common examples of these include: 

• dairy products

• caffeine 

• sweeteners

• alcohol

• onions

• fruit juices

The lifestyle changes you’re recommended will usually involve increasing the amount of exercise and physical activity you engage in already.

Losing weight is also often recommended for some people to help reduce the impact of IBS symptoms. But advice varies on a patient-by-patient basis, which is why it’s so important to work closely with your doctor. 

What IBS medications are available?

If dietary and lifestyle changes aren’t enough to alleviate the symptoms of IBS, there are certain medicines doctors may recommend. 

Many of these can be bought over-the-counter at a pharmacy without needing a prescription and will include medicines that directly target certain symptoms. 

For instance: 

• Antidiarrhoeal medicines and anti-motility drugs may help to treat diarrhoea
  

• Antispasmodic medicines may help alleviate stomach pain and excessive wind
  

• Laxatives may help to ease symptoms of constipation

If you’re struggling with IBS-related symptoms, your doctor will be able to provide you with tailored treatments based on your specific symptoms. So, make sure to reach out to them for their advice.

How does cannabis work as a medical treatment for gastrointestinal issues? 

The cannabis plant contains more than 100 cannabinoids, with two in particular that may be helpful in treating certain conditions like IBS. 

These are known as tetrahydrocannabinol (THC) and cannabidiol (CBD), which are both known to work in different ways within the body. 

THC is often affiliated with more psychoactive properties, leading to the “high” sensation many people associate with cannabis. 

Meanwhile, CBD is better known for its calming effects and anti-inflammatory properties, which is why it's of particular interest within gastrointestinal research. 

After all, many common gut-related symptoms, such as abdominal pain and discomfort, are thought to be linked to inflammation. 

While a lot more research is still needed, there is already a growing body of evidence showing that medical cannabis may help to alleviate certain symptoms of common gastrointestinal issues, like IBS. 

How do cannabinoids affect the gut? 

To fully understand why researchers are exploring medical cannabis for IBS, it’s important to know about the gut-brain axis and how it works inside our body. 

Put simply, the gut-brain axis is a two-way communication system that links your digestive system to your brain via the central nervous system. 

Within the context of IBS, it’s this system that’s theorised to play an important role in the symptoms it can cause, influencing everything from how your gut digests food to how painful your symptoms actually are. 

Running through this system is also what’s known as the endocannabinoid system (ECS), a complex cell-signalling network that helps regulate many important bodily processes, including gut motility and our ability to sleep. 

And this is where cannabinoids may be able to help. 

Cannabinoids, like THC and CBD, interact with the CB1 and CB2 receptors that the ECS uses to send messages around the body. 

In doing so, researchers believe that this interaction may influence some of the processes that lead to IBS symptoms, particularly in terms of abdominal pain and gut motility-related issues, and offer a potential treatment strategy for IBS.

Medical cannabis may also help to alleviate some of the secondary symptoms associated with IBS, such as sleep-related disturbances, and make certain triggers like stress easier to manage. 

What does recent research tell us? 

While the relationship between cannabinoids and IBS may be a subject of clinical interest, current research remains fairly limited. 

In fact, most of the clinical studies that are available have looked at medical cannabis and gastrointestinal issues more generally, rather than IBS specifically. 

For instance, a review published in Nature Reviews Gastroenterology & Hepatology in 2023 described the ECS as a logical target for treating IBS, due to its roles in gastrointestinal motility, inflammation and pain sensitivity. 

However, it also made clear that the effects of cannabis haven’t been properly assessed in large clinical trials and that further research was still very much needed. 

That said, it’s important to consider the patient voice as well. 

Back in 2025, we conducted the largest survey of active UK medical cannabis patients, gathering 1,669 responses. 

Of this number, 76 patients had been prescribed medical cannabis for a gastroenterological condition, such as IBS, Crohn’s disease or inflammatory bowel disease (IBD).

The results of this showed that 96.1% of patients believed their treatment was effective, with 97.4% saying it had improved their overall quality of life. 

Keen to learn more about these findings? Take a look at the full breakdown of results we recently published in honour of World IBD Day.  

Are there any potential risks or side effects of taking medical cannabis for IBS? 

As with most forms of medical treatment, there are certain side effects associated with taking medical cannabis. 

Some of the main examples of these typically include: 

• slight dizziness

• drowsiness

• nausea

• decreased appetite

• dry mouth

• mood-related changes

For a more detailed breakdown of these potential side effects, take a look at our dedicated article. Alternatively, speak to one of our specialists if you have any specific concerns you’d like to discuss. 

How do you take medical cannabis for IBS?

Medical cannabis comes in different formats that can be administered in various ways. 

For example, the treatment can typically be inhaled via a vaporiser, consumed via a pastille or dropped as oil under the tongue.

Regardless of the method your consultant prescribes for you, the dosage will always start low and be slowly increased over time, based on factors like your tolerance level, medical history, age, weight and specific IBS symptoms.

So, can medical cannabis help with IBS?

More research is still needed to understand the true potential of medical cannabis treatment for IBS, but recent evidence is showing promise in how it may reduce the pain and discomfort often associated with the condition. 

As with any type of medical treatment, it’s essential to speak to a trained healthcare professional before deciding whether medical cannabis may work as part of your treatment plan. 

Here at Releaf, we have a team of dedicated medical professionals who can answer any questions you may have about medicinal cannabis.

To see whether you might be eligible for a prescription, try our medical cannabis eligibility checker. It’s free, takes 30 seconds to complete and could help you find the gastrointestinal relief you’re looking for. 

Frequently asked questions about IBS and medical cannabis

Can medical cannabis help with IBS symptoms? 

Medical cannabis may be useful for some IBS patients, but it won’t work the same way for everyone. 

The best way to find out whether it’s a suitable option for you is to seek tailored advice from a specialist, such as our world-class clinical team here at Releaf.  

Can you get medical cannabis for IBS in the UK, and can a GP prescribe it?

Despite not being widely publicised in the press and media, medicinal cannabis is actually legally approved in the UK to treat certain conditions, and has been since November 2018.

However, it is very unlikely that a GP will be able to prescribe it. This is because prescriptions can only be administered by specialists registered to the GMC Specialist Register and dispensed by a CQC-regulated private clinic. 

Can cannabis worsen IBS or upset the gut? 

Yes, it can for some people. 

Taking cannabis affects everyone in different ways. While some patients will find it helps alleviate their IBS symptoms, others may notice certain side effects like nausea or appetite-related changes. 

This is why it’s so important to only ever take medical cannabis under clinical guidance. That way, the dosage and cannabinoid profile of your prescription can be tailored to meet your exact needs and symptoms. 

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