Irritable bowel syndrome (IBS) is a common gastrointestinal disorder characterised by recurrent abdominal discomfort, pain during defecation, or a change in frequency or consistency of stool. It is predominantly a disease of the large intestine. The exact cause of irritable bowel syndrome is still unknown.
Epidemiology
Studies have shown that more than a tenth of the worldwide population is living with IBS and many more are still living undiagnosed in this modern era. In Asia, there is an increasing prevalence in the more affluent city-states like Singapore and Tokyo, i.e. at 8.6% and 9.8% respectively, while the prevalence in India is as low as 4.2%.
Signs & symptoms of irritable bowel syndrome
The most common symptoms of IBS include:
- Abdominal pain or cramping
- Changes in the frequency of bowel movement
- Changes in the consistency of stool
- Bloating
- Mucus in the stool
More serious signs and symptoms include:
- Weight loss
- Diarrhoea at night
- Rectal bleeding
- Iron deficiency anaemia
- Unexplained vomiting
- Difficulty in swallowing
- Persistent pain that is not relieved by passing gas, or with bowel movement.
Risk factors of irritable bowel syndrome
The major risk factors for developing IBS are:
- Age <50 years old
- Female gender
- Family history of IBS
- Concomitant psychiatric illness – anxiety, depression, or other mental health issues.
- History of sexual, physical, or emotional abuse.
Symptoms of IBS can be triggered by:
- Certain food and beverages e.g. wheat, dairy products, citrus fruits, beans, cabbage, caffeinated and carbonated drinks
- Stress
- Hormonal changes – many women experience heightened discomfort from bloating and cramping during their periods.
Diagnosis
Usually, the diagnosis is clinical as there is no test to definitively diagnose IBS. Diagnosis is based on complete medical history, physical exam, and tests to rule out other conditions, such as celiac disease.
Additional tests that may be needed to rule out other diseases include:
- Stool routine and culture
- Colonoscopy
- X-ray or CT scan of the abdomen and pelvis
- Upper endoscopy
- Lactose intolerance tests
- Breath test for bacterial overgrowth
Treatment
The treatment of IBS is directed at symptomatic relief. The mild signs and symptoms can often be controlled by managing stress, modifying lifestyle and diet. Medications may be used as well.
Lifestyle changes
It is advised to:
- Avoid food triggers
- Avoid caffeinated, carbonated and alcoholic beverages
- Avoid foods high in FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols)
- These short chain carbohydrates create more fluid and gas in the gut causing pain, bloating and diarrhoea.
- E.g. of FODMAPs include:
- Dairy products containing lactose
- Products with high fructose (such as corn syrup)
- Artificial sweeteners (such as sorbitol/ mannitol/ xylitol/ maltitol/ isomalt)
- Gluten-rich foods such as wheat, barley and rye
- Legumes and cruciferous vegetables.
- Eat at regular times
- Drink plenty of fluids
- Quit smoking
- Exercise regularly
- Get enough sleep
Medications
Medications to help with pain
- Antispasmodics
- These reduce muscle spasms and pain in the digestive tract e.g. dicyclomine or hyoscine.
- Antidepressants
- Patients with moderate or severe IBS may benefit from taking an antidepressant
- Antidepressants may inhibit the activity of nerves that control the intestines to help reduce pain, alleviate anxiety and depression associated with chronic pain in IBS, as well as regulate abnormal bowel function.
- Tricyclic antidepressants (TCAs) e.g. amitriptyline or nortriptyline are useful in IBS-D;
- Selective serotonin re-uptake inhibitors (SSRIs) e.g. fluoxetine or paroxetine are useful in IBS-C.
For IBS with diarrhoea (IBS-D)
- Anti-diarrhoeal medications: These are over-the-counter medications, such as loperamide used to control diarrhoea. A bile acid binder, such as cholestyramine may be helpful but they can cause bloating.
- Alosetron: This medication acts on the muscles of the gastrointestinal tract to relax the colon. This slows the movement of waste through the intestines. Usually, it is given only for severe cases not responding to other treatments.
- Eluxadoline: This medication can ease diarrhoea by reducing muscle contractions and fluid secretion in the intestine and increasing muscle tone in the rectum.
- Rifaximin: It is an antibiotic that helps to decrease bacterial overgrowth in the gut.
For IBS with constipation (IBS-C)
- Fibre supplements: These can increase the bulk in your stool, making it easier to pass.
- Laxatives: Over-the-counter laxatives e.g. lactulose or polyethylene glycol can draw water into the colon to soften stool; the water increases stool volume and stretches the wall of the colon, triggering defecation.
- Lubiprostone: This medication can increase fluid secretion in the small intestine to help women who have IBS with constipation. This is generally prescribed only for women with severe symptoms that do not respond to other treatments.
- Linaclotide: It increases fluid secretion in the small intestine and helps in constipation.
Psychological therapies
Cognitive-behavioral therapy, standard psychotherapy, and hypnotherapy may be needed in IBS patients with depression or other mental illnesses.
Complications
- Haemorrhoids a.k.a. piles, due to straining from constipation
- Poor quality of life.
- Mood disorders, depression, or anxiety.
Conclusion
IBS is a very common digestive disorder affecting an average of 11.2% of people globally. Only a third of sufferers are formally diagnosed and even fewer are given some sort of treatment. This may be due to the lack of awareness about the disease or a lack of accessible health care facilities in developing and underdeveloped nations of Asia and Africa.
Symptoms of IBS may wax and wane, peaking with stress, hormone fluctuations, and illness. While there is no cure for IBS, symptoms can be managed well with lifestyle changes, medications or both.
