Introduction 

Crohn's disease is a chronic inflammatory bowel disease (IBD), that mainly affects the gastrointestinal tract. People with Crohn’s must consider many factors to manage the disease and keep inflammation and symptoms at bay. Symptoms can vary but common ones that many Crohn's patients share are abdominal pain, diarrhea, fatigue, and weight loss.

Though there have been advances in the development of medical therapies to treat Crohn’s, there is no cure. This is because there is simply not enough knowledge about the mechanisms causing the disease.

The management of chronic IBD has been increasingly studied in order to improve the quality of life in people with Crohn's disease. Interestingly, cannabis has shown potential benefits in helping manage the disease, and patients with Crohn’s have also started to show increasing interest in the use of medical cannabis to help their symptoms. This article explores the current research findings on the relationship between cannabis and Crohn's disease and the possible implications of this research.¹

What is Crohn's disease?

The chronic disease stems from an overactive immune system. It causes inflammation in the digestive tract, particularly affecting the small intestine and some of the large intestine but it is not limited to only these parts of the digestive tract. Because of the inflammation in Crohn’s, it is considered an inflammatory bowel disease (IBD).

The symptoms can vary from person to person, thus, the experience for each individual can be different. There are symptoms, however, which are more common than others, which can also vary in severity. When a flare-up occurs, for example, the symptoms can become excessive.^1,2

The main symptoms of Crohn's disease:

• Severe abdominal pain 
• Diarrhea 
• Extreme fatigue
• A loss of appetite and weight loss
• Anemia. This is considered a complication of Crohn’s

What causes Crohn's disease?

Crohn’s disease is still not fully understood, especially the specific causes and mechanisms. However, dysregulation of the immune system is thought to be the main cause of Crohn's disease. An abnormal immune reaction to the natural gut bacteria is what can cause inflammation but the exact intricacies of how this happens and what triggers this reaction isn't properly known, even now.

Other things can contribute to the development of Crohn’s, though these are not usually in a person's control. Factors such as genetics, a person's regular environment and gut bacteria have all shown to have possible influence on the development of Crohn's disease.³

Cannabis’ Potential for Crohns

There are many cannabinoids found in cannabis, all with different functions and therapeutic potential. The last few years have shown an increase in discussion surrounding medical cannabis use and its potential in the management of chronic disease and chronic pain.

CBD and THC are two of the primary cannabinoids which are in the highest concentration in cannabis. THC is a psychoactive cannabinoid, which is what results in the high feeling people usually sense, due to its effects of euphoria and psychosis. It can help with symptoms like pain in particular and is used for different diseases and severe pain management. Whilst CBD is not a psychoactive cannabinoid, it has also proved to have therapeutic effects for pain relief. It is usually the concentration of these cannabinoids which can alter the effects of its use.⁴

Since Crohn’s is a chronic condition, the use of cannabis has been explored in relation to alleviating chronic pain in Crohn's disease. Both positives and negatives of its use have been suggested but there has been no firm decision on its effectiveness in people with Crohn's disease and their symptoms and flare-ups.⁵

Research findings

Overall, the current research is mostly limited in terms of exploring cannabis as an effective treatment for Crohn's disease. However, from the research that is available, there have been beneficial findings to evidence of cannabis’ potential in alleviating symptoms, particularly pain, which is one of the major symptoms in people with Crohn’s.

Medical cannabis has been shown in certain studies to aid inflammation because of its anti-inflammatory properties.

Safety and effectiveness of cannabis treatment for Crohn's disease were reviewed in a study conducted in 2020.⁶ In this study, the effects were uncertain. However, some mild adverse effects were reported which are usually consistent with cannabis use. These included nausea, confusion, dizziness, memory loss, difficulty concentrating and sleepiness.

Other studies have shown that patients have reported the use of cannabis beneficial for pain relief in Crohn's disease. However, no evidence could prove any benefits to help inflammation in the bowels. This research suggests symptomatic relief rather than any benefit of cannabis in treating the root cause of the disease.⁷ Similar studies have also reported the same results, that overall cannabis helped moderately improve clinical symptoms but had no significant effect on inflammation.⁸

There has been some evidence to show remission in people who used cannabis cigarettes compared to those using a placebo. Adverse effects such as nausea and memory loss, though mild, were also more likely to be seen in the cannabis users. Overall however cannabis users themselves reported feeling improvements in pain and appetite.⁹

Cannabis could possibly worsen the prognosis of patients with Crohn's disease. Whilst some of these studies have shown symptomatic improvement for people with Crohn’s, a particular study conducted in 2014 concluded that cannabis was associated with a worse prognosis of the disease. It did however show that the short-term symptoms like pain and diarrhea associated with inflammatory bowel disease were improved.²

Limitations in research

With most research, limitations of the studies can arise. It's important to understand the limitations of this research and be aware of what they are.

Limitations of the reach into cannabis use for treatment of Crohn's disease⁹:

• Small sample sizes. Not enough people are included in a study to be able to generalize the results
• There are too few studies to confidently support and confirm the data and results of research conducted
• Some of these studies have relatively short treatment periods, meaning only short-term effects are observed

Overall the general agreement is that there is just too little research into the relationship between cannabis and crohns to confidently suggest cannabis as a beneficial treatment.

Further studies however have been urged and are of high importance to increase our understanding on the effect of cannabis on people with Crohn's disease.⁸

Safety and side effects 

It's important to understand that medical cannabis and its effectiveness for Crohn's disease treatment is something that has not been established fully.

The lack of studies means that there is an overall lack of understanding about the effects, particularly the negative side effects. Because of these gaps in research, the safety of cannabis use for Crohn’s cannot be guaranteed. It's important to acknowledge that regardless of the therapeutic effects of cannabis, several adverse effects can be expected when using the drug. Though these may be subtle and not necessarily severe, they should still be considered when deciding to use cannabis.^2,7

Adverse effects of cannabis use:

• Anxiety
• Panic attacks
• Disorientation and dizziness
• Short term memory
• Impaired attention
• Nausea

Future direction of research findings 

More studies need to be carried out for accurate and conclusive results on how cannabis affects those with Crohn's disease. There is a current lack of research exploring maintenance treatment using cannabis as well as relapses. The main issue is that at present, the overall evidence leaves researchers uncertain about both the benefits and harms of cannabis in those with Crohn's disease.⁶

It's also been suggested that studies with a higher number of participants need to be carried out for more definitive results about cannabis safety and effectiveness in Crohn's disease.

Factors like dosages, cannabinoid combinations and varying modes of delivery are all important factors which also must be explored in much more detail.⁸ It is clear that there is some promise for the therapeutic use of cannabis to alleviate symptoms in Crohn's patients. However until further research is undertaken, no definitive suggestion can be made to guarantee its effectiveness or safety.

Summary 

Many people can struggle to manage Crohn's disease, particularly the more significant and life-altering symptoms like pain and diarrhea. Though there are some medications to help deal with the disease, the use of cannabis as a possible therapeutic to help symptoms has been discussed. Various studies have been done and different results proposed, varying from the usefulness of cannabis in alleviating pain to the possible negative effects of the drug for the treatment of Crohn's. Though there is some research, it is overall limited and there is not an evidence-based consensus to definitively define cannabis as a helpful aid or treatment for Crohn’s. Future research and more detailed studies are needed to truly understand the relationship between cannabis and Crohn's disease management and draw firm conclusions on the matter.