How can Crohn disease cause fistulas and abscesses?

Crohn disease is a chronic inflammatory bowel disease that causes significant damage to the digestive tract, particularly beneath the mucosa. This deep-seated inflammation can lead to the development of fistulas, which are abnormal passages or ducts that connect the bowel to other organs, such as the bladder or vagina.123

These fistulas often serve as pathways that lead to the formation of abscesses, which are painful, pus-filled cavities that develop within the tissues. The formation of these fistulas and the associated thickening of the intestinal wall are key clinical features that help distinguish Crohn disease from ulcerative colitis. Because these complications can lead to severe health issues, including infection and malnutrition, they often require medical intervention, such as immunosuppressive therapy or surgical repair.132