Irritable bowel syndrome (IBS) is a common digestive disorder diagnosed mainly on the basis of symptoms, after other important causes have been excluded. There is usually no single laboratory test that confirms IBS.
IBS is increasingly understood as a disorder of gut-brain interaction. The brain and intestines communicate continuously through nerves, hormones, immune signals and chemicals produced by the trillions of microorganisms living in the gut. This helps explain why stress, poor sleep and emotional changes can influence bowel symptoms.
Typical symptoms include recurrent abdominal pain, bloating, excessive gas and changes in bowel habits. Some people mainly experience constipation (IBS-C), others diarrhoea (IBS-D), while some alternate between the two.
Constipation is particularly common as people grow older. It can be associated with inadequate fibre intake, insufficient fluids, physical inactivity, certain medicines and changes in bowel function and gut bacteria.
First, drink sufficient water regularly, unless you have been advised to restrict fluids because of a medical condition.
Second, gradually increase your intake of fibre-rich plant foods including vegetables, fruit, whole grains, beans and other legumes. Fibre intake should be increased slowly because suddenly eating large amounts may worsen bloating in some people with IBS.
Third, establish a regular toilet routine. Sitting on the toilet for 5-10 minutes after breakfast can take advantage of the natural reflex that stimulates the bowel. Do not ignore the urge to pass a stool. Resting your feet on a small footstool can also make bowel movements easier and reduce straining.
Fourth, keep physically active. Regular walking can help stimulate bowel movements.
If these measures are insufficient, medical advice may be needed. Some medicines can cause constipation, and an appropriate laxative may sometimes be necessary.
The gut-brain connection becomes particularly interesting when we consider neurological disorders. Research has found associations between gastrointestinal problems, changes in the gut microbiome and conditions such as Parkinson’s disease and cognitive impairment.
However, an association does not mean that IBS or constipation causes these conditions. The relationship is complex and is still being investigated. In some people with Parkinson’s disease, constipation can occur years before movement symptoms become apparent.
Dietary changes, regular physical activity, adequate sleep and stress management can be important components of IBS management. Fermented foods may also support a healthy gut microbial environment, although they are not a universal treatment.
The gut is much more than a tube through which food passes. It is a communication centre connected to the brain, immune system and the rest of the body.
The message is simple: look after your gut, and you may also be supporting your brain.
However, blood in the stool, unexplained weight loss, anaemia, persistent vomiting, severe abdominal pain or a new change in bowel habits, particularly in an older person, should not simply be attributed to IBS. These symptoms require medical assessment.
