Diverticular disease is the commonest "abnormal" finding at colonoscopy. It tends to be commoner as patients age and usually arises in those over 50 years of age. However some patients develop diverticular disease when they are in their 30’s and 40’s. There is an association with diet, smoking and hereditary. One particular gene, TNFSF 15, appears to be linked to the likelihood of more severe disease. In western patients disease is often worse on the left side of the colon, whereas in those from the eastern hemisphere right sided disease is more prevalent. Roughly 7 out of ten eighty year olds will have diverticular disease.

Diverticula are hernias, or small “outpouchings” which develop at areas of weakness where blood vessels perforate the colonic wall in order to supply the lining of the bowel with blood. Over many years a small area of weakness can become an indentation and then a small pocket. This is known as a diverticulum – a latin word for a house of mischief, usually off the “main street”.

Most people are asymptomatic. Only a small proportion ever develop problems. Approximately 5% -20% ever get an episode of diverticulitis. Young patients are more likely to develop complication from diverticular disease such as diverticulitis. Patients under fifty with diverticular disease are roughly twice as likely to develop diverticulitis and its associated complications than those over 65 years of age. Some patients also develop a segmental colitis which is often regarded as a form of diverticulitis, 

Is it irritable bowel syndrome or diverticulitis causing may pain and urgency?

Low grade inflammation within a segment of diverticular disease may lead to increasing fibrosis in the surrounding tissues. This fibrosis can lead to a decrease in the flexibility of the bowel wall making it stiffer and less compliant. If patients then develop inflammation either because of an acute episode of diverticulitis or because of other causes such as gastroenteritis this may lead to increasing sensitvity in the bowel. The combination of these factors can lead to urgency and frequent passage of normal stools as a result of the loss of bowel wall compliance and the increasing sensitivity to pressure in the affected bowel. Approximately 5% -20% ever get an episode of diverticulitis. Young patients are more likely to develop complication from diverticular disease such as diverticulitis. Patients under fifty with diverticular disease are roughly twice as likely to develop diverticulitis and its associated complications than those over 65 years of age. It is some times difficult to differentiate between symptoms due to diverticular disease and this increasing fibrosis and sensitvity and those of irritable bowel syndrome. Indeed many older patients may have both conditions which co-exist. When symptoms of discomfort and urgency arise the ways by which they do so may share common mechanisms.