Inflammatory bowel disease takes two forms: ulcerative colitis and Crohn's disease, both of which are more virulent than irritable bowel syndrome (IBS), with which the disease is sometimes confused. After a sufficient period, it is possible to clearly diagnose the disease. Parts of the intestine become inflamed and food may not be absorbed properly. Sometimes the diseased part of the bowel is surgically removed. The causes of the disease are not known, but there may be a genetic predisposition to Crohn's disease. In addition, diet and emotions, such as anxiety and feelings of stress have been weakly linked to the disease. IBS is considered a “gut-brain disorder”, since it is often worsened by stress. Half of IBS sufferers also have difficulties with depression or anxiety. Ongoing research is investigating whether gut bacteria are one reason for the mood symptoms in IBS, as well as the gastrointestinal pain, diarrhoea and constipation.
Inflammatory bowel disease is much less common than IBS, which shares some of the same early symptoms. Inflammatory bowel disease affects women and men equally often.