Since the surface of the skin at the anus has been worn away, defecation irritates the fissure and may cause the sphincter muscles to spasm, resulting in intense pain. Fissures are often associated with constipation or inadequately emptied stools, and may also be linked to stress or hemorrhoids.
Flexible endoscopy is also useful in establishing a diagnosis.
Surgery is generally unnecessary but may be recommended in severe cases. After the fissure heals which may take 2 to 3 weeks a sigmoidoscopy may be performed to check for other rectal problems. Physical examination identifies the problem, but the precise location of the fistula's source can be ascertained through anoscopy. Proctosigmoidoscopy is necessary to exclude inflammation or underlying intestinal disease. Imaging techniques such as barium enema or CT scan may be needed to examine complex fistulas that may accompany Crohn's disease.