Irritable Bowel Syndrome (IBS) is a common condition resulting from various disorders of the digestive tract. IBS affects millions of people worldwide. It is estimated that in Poland, up to 20% of the adult population suffers from it. IBS symptoms most commonly appear after the age of 30 and are twice as common in women. Although it affects such a significant proportion of the population, patients often do not receive effective treatment. The key to treatment is a personalised, multi-pronged approach. There is no single standard protocol that works in all cases, as IBS has many different manifestations and a complex aetiology that can vary from patient to patient.

Symptoms of Irritable Bowel Syndrome

1. Abdominal pain: Patients with IBS often complain of pain and discomfort in the abdomen, particularly in the lower abdomen, which can vary in intensity and location. Very often, the pain comes on suddenly, for example after a meal, and the patient feels an immediate urge to use the toilet.   
2. Irregular bowel movements: people with IBS may tend to suffer from diarrhoea, constipation or a combination of both.
3. Bloating and flatulence: bloating is a common symptom of IBS that can cause discomfort and a feeling of tightness in the abdomen.
4. A feeling of incomplete bowel movement.
5. Traces of mucus in the stool.
6. General symptoms include, among others: fatigue, low mood, depression and headaches.

Reasons

Irritable Bowel Syndrome very often arises from digestive disorders, accompanying, amongst other things: intolerances (to gluten, lactose, FODMAP foods), food sensitivities (e.g. to gluten, milk, eggs), disorders of gastric acid secretion, and disorders of bile acid secretion and absorption. The condition most commonly leading to IBS is SIBO, or small intestinal bacterial overgrowth. It is estimated that IBS affects up to 80% of patients with SIBO.

An important factor in the aetiology of IBS is intestinal dysbiosis, i.e. an imbalance between the microorganisms that make up our microbiota.In IBS, a reduction in the number of Lactobacillus and Bifidobacterium bacteria has been observed, along with an increase in Escherichia coli, Streptococcus, Clostridium spp., as well as a change in the ratio between Bacteroidetes and Firmicutes. Intestinal dysbiosis can result from a variety of factors, such as infections (bacterial, fungal, parasitic), antibiotic therapy, and the overuse of certain medications (including popular proton pump inhibitors used to treat heartburn and reflux). Dysbiosis is a common factor in most digestive problems.

Dysbiosis in patients with IBS is also associated with impaired intestinal motility, visceral hypersensitivity, disorders of the gut-associated lymphoid tissue (GALT) and disorders of the central nervous system. Increased visceral hypersensitivity may result from disturbances in the generation, transmission and interpretation of sensory stimuli, or be the result of an abnormal response to these stimuli. There is a link between hypersensitivity of sensory nerve endings in the gut and increased production of neurotransmitters such as serotonin and substance P. Serotonin plays a key role as a neurotransmitter, and almost 95% of the total amount of this substance is found in the gastrointestinal tract. Recent research has enabled the identification of serotonin receptors, opening up new possibilities for the use of drugs that act on these receptors and the development of innovative treatment strategies for IBS.

Stress is a significant factor in the development of irritable bowel syndrome (IBS). Evidence from clinical and experimental studies shows that stress has a marked effect on: the composition of the microbiota, intestinal sensitivity, motility, secretory functions and the maintenance of intestinal barrier integrity. Stress-induced changes in neuro-endocrine-immune pathways affect the gut-brain axis and the microbiota-gut-brain axis, leading to an exacerbation of IBS symptoms. As this is a stress-sensitive disorder, stress management has a place in the treatment of IBS. Currently, pharmacological strategies that target stress-related changes, such as antidepressants, antipsychotics, 5-HT synthesis inhibitors, selective serotonin reuptake inhibitors, and specific 5-HT receptor antagonists or agonists, play a key role in the treatment of IBS. Psychotherapy and ‘groundwork’, i.e. regulating the circadian rhythm, also play an important role.

Addressing the underlying causes that may contribute to the development of IBS helps to provide more effective care for the patient, rather than merely treating the symptoms.

Diagnostics

In the diagnosis of IBS, we use the Rome Criteria, which are updated by the International Society for the Study of Irritable Bowel Syndrome (Rome Foundation); the latest version, Rome Criteria IV, was introduced in 2016. To meet the criteria for IBS, a patient must have experienced symptoms for at least 6 months, occurring on at least three days per month.

The Rome IV criteria cover three main subtypes of IBS:

• IBS with predominant abdominal pain (IBS-D): diarrhoea occurs more frequently than constipation, and lower abdominal pain is the main symptom.
• Irritable bowel syndrome with predominant constipation (IBS-C): constipation is more common than diarrhoea, and abdominal pain is also present.
• IBS with alternating diarrhoea and constipation (IBS-M): patients experience both diarrhoea and constipation, with no clear predominant symptom. Pain is also present.

In the case of IBS, a comprehensive diagnosis is essential, as the condition can present with a whole range of symptoms that are also characteristic of many other digestive disorders. In each patient, a variety of causes may overlap, which is why it is vital to identify them and implement targeted treatment.

Which doctor diagnoses IBS?

The doctor who makes this diagnosis may be a gastroenterologist; however, specialists in functional medicine and clinical dietitians also treat this syndrome.

Treatment

Treatment for IBS often involves merely managing symptoms. Painkillers, antispasmodics, anti-diarrhoea medicines, and medicines that regulate bowel movements are the most commonly prescribed, but they do not address the underlying causes. Modern medicine, including functional medicine, has much more to offer patients, such as a more comprehensive medical history and diagnostic tests carried out to rule out other conditions that may be the underlying cause or contributing factors of IBS. Eliminating these causes and factors leads to better and more long-term results. 

Diet therapy

A carefully tailored diet can be a highly effective therapeutic tool. For it to work, it must be tailored to the individual, which requires a full assessment. Based on this, a dietitian draws up a meal plan that temporarily restricts food groups which trigger IBS symptoms in the patient, or which the patient cannot tolerate or fully digest. Herbs and other dietary supplements, including probiotics, are also often an important part of the treatment; these help to reduce inflammation in the gut, support the growth of beneficial microorganisms, reduce the number of pathogens and improve gut barrier function. 
In 2019, a study was conducted involving patients with IBS, in which one group of participants was treated with an antibiotic in combination with a probiotic containing the Bifidobacterium Longum W11 strain, soluble fibre and B vitamins, the second group was treated with an antibiotic, followed by a recommended LOW FODMAP diet, and the third group with a spore-based probiotic, Bacillus MegaSporeBiotic. The effectiveness of the treatments was assessed based on quality of life scores and a scale measuring the severity of symptoms such as abdominal pain and bloating. All three groups managed to reduce symptoms and improve patients’ quality of life to a comparable extent; however, the group taking Bacillus spores achieved this without the use of antibiotics. 

Summary

Irritable Bowel Syndrome is a very common condition that can significantly affect patients’ daily lives. It should be understood as a set of symptoms that are manifestations of various conditions and disorders within the digestive system, requiring thorough diagnosis and a tailored, multi-pronged treatment approach.

Edyta Grabowska-Szymczak

psychodietician, functional medicine specialist

The content of this article was reviewed by Edyta Grabowska-Szymczak, a psychodietician and specialist in functional medicine. She specialises in gastrointestinal disorders such as SIBO, IBS, GERD, coeliac disease, histamine intolerance, as well as autoimmune and endocrine disorders. In her work with patients, she combines the latest medical nutritional therapies with proven natural methods.

Sources:

1. Catinean A, Neag AM, Nita A, Buzea M, Buzoianu AD. Bacillus spp. Spores—A Promising Treatment Option for Patients with Irritable Bowel Syndrome. Nutrients. 21 August 2019;11(9):1968. doi: 10.3390/nu11091968. PMID: 31438618; PMCID: PMC6770835.