What is it, and who gets it?

Irritable bowel syndrome (IBS) is a chronic condition characterised by abdominal pain, bowel dysfunction, and abdominal bloating in the absence of any structural abnormality. A number of pathophysiological abnormalities, however, can often be identified.1 About 10-15% of the adult population in the United Kingdom is affected by irritable bowel syndrome.2

Aetiology

IBS is now clearly understood to be a multifactorial condition, with a variety of factors contributing to expression of the disease rather than its just being due to psychopathology. These include motility, visceral sensation, central processing, genetics, dietary factors, inflammation, and neurotransmitters.1

Exacerbating factors

Stress exacerbates IBS rather than being causative in any way. If stress is severe and chronic—for example, stress caused by continuous domestic strife—it can result in the disorder being virtually untreatable.3

Antibiotics need to be used with care in patients with IBS. Some antibiotics, particularly erythromycin, can make the condition worse.4

Non-steroidal anti-inflammatory drugs are often prescribed for the pain associated with IBS, but they may exacerbate symptoms. Paracetamol does not upset IBS.5

How do I diagnose it?

In the absence of a specific diagnostic test, the diagnosis remains largely clinical.