Irritable bowel syndrome
What is IBS?
Irritable bowel syndrome is the term used to describe a group of disorders in which the normal function of the gastrointestinal tract is disturbed without obvious inflammation or damage to the structure of the bowel. The cause of IBS is not fully understood but it is thought to occur due to disturbance of the normal function of the muscles of the gut (dysmotility), the nerves supplying the gut (hypersensitivity) and the microbiological makeup of the gut contents (dysbiosis).
IBS is very common, affecting as many as 1 in 5 people during their lives. The main symptoms of IBS are abdominal pain, bloating, chronic constipation, chronic diarrhoea or alternating constipation and diarrhoea. The symptoms of IBS often come and go but may be chronic. IBS is more common in women and often starts in the late teens, twenties or thirties. Sometimes IBS can occur after an episode of gastroenteritis (post-infectious IBS) and in this case the symptoms often resolve after a period of time.
Is IBS serious?
The symptoms of IBS may be very distressing but, fortunately, IBS never results in damage to the gut, problems with nutrition or more serious conditions.
How do you diagnose IBS?
The diagnosis of IBS can sometimes be made just by talking to your doctor. If the symptoms are typical then testing may not be required to confirm the diagnosis or exclude other causes. Certain features are never a part of IBS. These include bleeding, weight loss and fever. These symptoms should lead to further testing.
Testing is usually carried out if your symptoms start after 40 years of age, there are any unusual features to the symptoms or there is a history of bowel cancer, inflammatory bowel disease or coeliac disease in your family. The tests used may include blood tests, stool tests, radiology (ultrasound or CT), or endoscopy (gastroscopy and/or colonoscopy).
What is the treatment for IBS?
There is no cure for IBS. The goal of treatment is to manage the symptoms of the condition. Treatments should be tailored to the symptoms. No single treatment works for all patients and successful management will often require trialling several different approaches.
Diet and stress often contribute to IBS or make the symptoms worse and it is important to systematically identify any dietary triggers. A food diary can sometimes be helpful to identify foods or food additives that are exacerbating the symptoms.
Dietary measures such as increasing (or sometimes decreasing) dietary fibre, avoiding poorly absorbed food components such as fructose, sorbitol, starch and lactose, or reducing alcohol, caffeine and fatty foods may be helpful in some patients. An experienced and qualified dietician may play an important role in helping people deal with IBS.
Medications that relieve spasm such as Buscopan and Colofac may help pain and bloating. Anti-diarrhoeal medications may be useful in those with diarrhoea and laxatives can help those with constipation. Low doses of antidepressant medications have been shown to be helpful in some patients with IBS even in the absence of depression.
Management of stress may be an important part of controlling the symptoms of IBS.