Is irritable bowel syndrome a real condition, or is it all in your head?

IBS is a real, physically demonstrable condition. In people with IBS, the communication between the gut and the brain is measurably disrupted. Bowel movements are abnormal, pain sensitivity from the abdomen is heightened, and the central nervous system processes gut signals differently than it does in healthy people.

One of the clearest indications that IBS has a physical origin is its link with gut infections. After an acute gastrointestinal infection, the risk of later developing IBS is considerably elevated. That is difficult to put down to being 'all in your head' when it starts with a bacterium or virus. Moreover, measurable abnormalities have been found in a proportion of patients: a more permeable gut wall, a disrupted composition of gut bacteria, low-grade inflammation, and abnormalities in the production of serotonin in the gut.

The fact that IBS is more common in people with anxiety or depression is accurate, but the sequence is not always one in which psychological complaints come first. In a large group of patients, the gut symptoms actually predate the mood problems. The fact that psychological treatments can reduce symptoms also says nothing about the origin: such therapies help with migraine, chronic pain, and heart failure too, without anyone calling those conditions 'imaginary'.

IBS is estimated to affect 5 to 21 percent of the population, depending on how the diagnosis is made. The condition has a major impact on daily functioning, capacity to work, and quality of life, and patients make significantly greater use of healthcare. The diagnosis is made on the basis of symptoms and by ruling out other bowel diseases. If you also have warning signs such as unintentional weight loss, blood in the stool, or anaemia, always discuss these with your doctor.

IBS is probably not a single disease but a collection of conditions with similar symptoms but different underlying causes. Research into the gut microbiome shows that specific changes in gut bacteria are associated with particular symptom patterns. Treatment aimed at the specific mechanism in each individual patient appears promising, but is not yet standard in everyday practice.