Irritable Bowel Syndrome

What is IBS?

Irritable bowel syndrome (IBS) is one of the most common of all medical disorders worldwide, in fact it is the most commonly diagnosed gastrointestinal disorder (1). The severity of IBS symptoms can range from mild discomfort in the form of bloating, gas, constipation and/or diarrhoea; to debilitating pain which can reduce one’s ability to work, travel and socialize. Women are 1.5 to 3 times more likely to have IBS than men (2).

Despite an estimated prevalence of 10-15% across Europe, only 3% of the population are formally diagnosed with IBS. This is a consequence of sufferers either not seeking medical attention or being misdiagnosed. Although a blood count can be used to help confirm the presence of the disease, international best practice guidelines promote positive diagnosis using the Rome criteria (Table 1). These criteria take a symptom-based approach, identifying the presence of abdominal discomfort/pain; altered bowel habits; and the absence of any other diseases which could cause similar symptoms (4). Some commonly known triggers include food, early life stressors, antibiotics and/or altered brain-gut interaction (1).

Rome IV IBS Diagnostic Criteria
Recurrent abdominal pain at least 1 day/week in the last 3 months, with two or more of the below criteria:

  1. Excretion-related
  2. Associated with a change in frequency of depositions.
  3. Associated with a change in stool appearance.

Although IBS is believed to be a lifelong relapsing condition, it should be noted that studies find that the disease prevalence decreases in ages above 50; implying that symptoms do in fact remit overtime. The symptoms experienced can vary greatly between individuals. Furthermore, a single individual’s symptoms can vary over a prolonged period of time, so much so that a sufferer may go from experiencing one type of IBS to another in their lifetime.

What are the different types of IBS?
Constipation-predominant IBS. Specific symptoms include infrequent and hard stools - alongside other general IBS symptoms such as stomach pain, bloating, cramps, lack of energy, backaches and problems peeing.
Diarrhoea-predominant IBS. Regular symptoms include frequent and loose stools, alongside other general IBS symptoms.
Mixed type of IBS. Symptoms alternate between constipation and diarrhoea. This subtype typically causes more discomfort than IBS-C and IBS-D.

Conventional treatments

During the last 5 years, lifestyle and dietary changes have become the first-line treatment route for IBS patients. Physically active individuals have more regular bowel movements; furthermore, structured exercise routine apparently leads to even better results. Hence, a minimum 20 minute walk a day is recommended for IBS patients, as it provides regular bowel movements through routine exercise.
Since food is a trigger in majority of IBS sufferers, doctors typically recommend keeping a food diary to start identifying and isolating trigger foods from diet. The most recognised and effective change is to adopt a low FODMAP diet. FODMAPs are fermentable short chain carbohydrates and sugar alcohols which are poorly absorbed by the body, resulting in pain and bloating.
Although the cause of IBS is still unknown, a link has been identified between the disordered regulation of the gut-brain axis (communication between the gut and the brain) and IBS symptoms (8). This link highlights the psychological dimension of IBS which explains the growing use of anti-depressants and anti-anxiety medication to treat IBS. There is good evidence to suggest that tricyclic antidepressants (TCAs) and selective serotonin releasing inhibitors (SSRIs), improve abdominal pain and the collective symptoms of IBS, respectively.
Traditional pharmacological treatments, applied to IBS, are ineffective on the basis that they do not cure any problem at its root, only palliate or attempt to annul the most serious symptom, as we have said before, presenting not only unsatisfactory results, but also terrible side effects, a direct cause of the manipulation of biorhythms in this way, so unbalanced and disrespectful to the body. The side effects, especially in laxatives, have also triggered a clear fall in confidence in these products and therefore in their distribution and consumption. In conclusion, and following the course of treatment by the chemical route, we have noticed increasing cases of patients who seek in antidepressants the main solution to the problem and offer great results in diarrhea and constipation, which leads us directly to the next point, which is very interesting.

The Gut-Brain Axis and the Psychological Dimension of IBS

To truly understand the symptoms of IBS, one needs to understand the way the gut and the brain communicate with each other, also known as the gut-brain axis. The gut is known as the second brain, as it forms the enteric nervous system (ENS). The central nervous system (CNS) - made up of the brain and spinal cord – connects to the ENS both physically and chemically.
The chemical link between the gut and brain is made by neurotransmitters. A neurotransmitter you may be familiar with is the ‘happiness hormone’: serotonin. This, as well as other neurotransmitters, can be produced both in the gut and the brain. Thus, just as a troubled brain can send signals to the gut, giving you an uneasy ‘gut feeling’; a troubled intestine can send signals to the brain, inducing feelings of stress, depression, anxiety or fear.
Not only have studies shown that stress - acute or chronic – exacerbates IBS symptoms, but the commonness of anxiety or depression amongst sufferers implies that brain function may be disordered in people with IBS. It is unknown if one causes the other, but what is certain is that the presence of anxiety disorder and/or depression alongside IBS forms a vicious cycle of worsening symptoms. Every gut organ and therefore every gut function is vulnerable to the effects of stress; hence why long-term follow ups show that symptoms of IBS typically worsen over time for those suffering with depression. It is important to be aware of these links, not only for clinical investigators, but for sufferers as it provides a personally meaningful explanation for the development of his/her symptoms.

Comorbidities: Other Diseases That Commonly Exist in Tandem with IBS

An inclusive - but not exhaustive - list of conditions frequently reported to be associated with IBS:

● Depression
● Anxiety disorder
● Fibromyalgia (causing severe pain spread throughout the body accompanied by
emotional stress)
● Chronic headache/cephalea and migraine
● Chronic back pain
● Chronic pelvic pain
● Temporomandibular joint disorder
One or more of these functional conditions exists in roughly half of all IBS sufferers. Furthermore, patients with IBS are twice as likely to have these conditions than the general population. Research has confirmed that underlying endocannabinoid deficiencies play a role in IBS, migraine, fibromyalgia and a growing list of other medical conditions. This brings us to our next question.

Can Hemp Help?

Given the link identified between underlying endocannabinoid deficiency and the presence of IBS in patients, cannabinoid medicines may hold the answers that so many are looking for. This is due to the active role of the endocannabinoid system (ECS) in controlling gut balance, known as homeostasis.
The main roles of the ECS in the gastrointestinal tract includes modulation of visceral sensation; intestinal inflammation; and the gut-brain axis - all functions that appear to be dysregulated in IBS.
A concept for re-balancing the ECS and managing endocannabinoid deficiency is use of phytocannabinoids: cannabidiol (CBD) and tetrahydrocannabinol (THC). Phytocannabinoids are plant derived and could supposedly substitute for endocannabinoids (which are produced within our bodies). THC has an infamous name for being the psychoactive compound in cannabis which produces the ‘high’ sensation; however, we should shed some light on the clinical trials which have provided evidence of clinical efficacy and safety of THC in treating abdominal spams and pain. It is believed that CBD synergises the effect of THC, further alleviating physical IBS symptoms .
Apart from targeting the physical symptoms of IBS, cannabinoids also show potential for managing the psychological side. CBD possesses anti-anxiety, antipsychotic and neuroprotective properties
It’s promising role as a therapy to manage anxiety disorders simultaneously provides hope on it’s potential for managing IBS, through helping break the vicious cycle between poor mental health and poor gut health.


In general, the efficacy of drug therapies for IBS is weak, hence why ≤50% of people turn to alternative medicines. More randomised clinical trials are required to bridge the gap in understanding the IBS mechanism and the use of cannabis-based medicine. Regulating diet and adhering to a consistent exercise routine should still be regarded as the first-line treatment; however, combining with alternative cannabis-based medicine could lead to enhanced management of symptoms and general well-being.


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