A common 'functional' disorder of the gut, Irritable Bowel Syndrome (IBS) is on the rise. But its very nature as a functional disorder, which means that there are symptoms but no visible abnormality in the structure, makes it difficult to diagnose.

Figures suggest that up to 1 in 5 people in the UK will develop Irritable Bowel Syndrome at some stage in their life, usually appearing first in young adults and teenagers. For reasons that are not clear, women are more often affected than men.

So what are the symptoms of Irritable Bowel Syndrome? They vary widely, but the most common ones include:

Abdominal pain - this can occur in different parts of the abdomen, and often eases after you pass wind or stools (faeces)
Increased wind
Abdominal bloating or swelling
Diarrhea
Constipation
Sudden need to get to the toilet quickly (e.g. a 'morning rush')

The symptoms are just a few of the common ones experienced by people with IBS, with most people experiencing a combination of these at different times.

The cause of IBS is unknown, but may include:

Hyperactivity of the nerves or muscles of the gut
Intolerance to certain foods
Infection and bacteria in the gut