About one in every three people with Crohn’s disease will develop a fistula. Fistulas are abnormal passageways that connect two parts of the bowel together. They can also connect the bowel to the bladder, vagina, or outside skin. Fistulas occur when severe inflammation spreads through the bowel wall, creating a tunnel to another area.
Symptoms of a fistula can differ depending on where the tunnel formed. An internal fistula may cause general symptoms such as diarrhea or malnourishment because food is bypassing a section of the bowel and is unable to be absorbed. Fistulas connecting the bowel to other areas may produce more specific symptoms. For example, a fistula between the intestine and the skin may cause leaking of mucus, pus, or stool from the area.
Pay close attention to your body and talk with your doctor if you have unexplained symptoms. Your doctor can help close a fistula, reducing or eliminating related symptoms. Treatment often involves medication and sometimes surgery.