Appendix removal delays onset of inflammatory bowel disease and lessens symptoms

Appendix removal delays the onset of inflammatory bowel disease and lessens the symptoms, especially if done before the age of 20, finds research in Gut.

Crohn’s disease and ulcerative colitis are the most common forms of inflammatory bowel disease and affect around 5 in every 1000 people.

The researchers based their analysis on a survey of patients registered with the Brisbane Inflammatory Bowel Disease Research Group between 1995 and 1999. They included 307 patients with Crohn’s disease and 335 with ulcerative colitis.

The patients were asked detailed information about the diagnosis and course of their disease, including treatment, the reasons for, and amount of, intestinal surgery they had had, and if they had had their appendix removed.

This group was then compared with the same number of people randomly selected from a twin registry, who were also asked about lifestyle factors and appendix removal.

The findings showed that around one in five (60) patients with ulcerative colitis had undergone surgery (removal of their colon) to control severe disease that was unresponsive to drugs. Almost one in four had been treated with immune suppressant drugs.

Over 40% of patients with Crohn’s disease required this type of medication, while 60% had undergone surgery at least once to ease intestinal symptoms.

As expected, smokers were twice as likely to have Crohn’s disease, but less likely to have ulcerative colitis.

But the most striking results were found for appendix removal. Twins were over three times as likely to have had their appendix removed as patients with ulcerative colitis and more than twice as likely as those with Crohn’s disease. Appendix removal before the age of 20 strengthened this finding for both forms of inflammatory bowel disease.

Patients with ulcerative colitis who had had their appendix removed also had milder disease and did not require either as much surgery or immune suppressant drugs as those with the disease but an intact appendix.

The findings also indicated that patients who had undergone prior appendix removal were older when they were first diagnosed, suggesting that the operation may even delay the onset of both ulcerative colitis and Crohn’s disease in susceptible patients.

It could be that the appendix is involved in prompting the gut’s immune system, including the production of antibodies to bacteria, say the authors. Removal of the appendix early in life may leave the gut “immunodeficient,” but in those people who are genetically susceptible to inflammatory bowel disease, this may be protective.