Lateral internal sphincterotomy versus 0.25 % isosorbide dinitrate ointment for chronic anal fissures: a prospective...

To compare the healing properties of lateral internal sphincterotomy (LIS) and isosorbide dinitrate (ISDN) ointment for chronic anal fissure.

Patients with a chronic anal fissure were randomly assigned to a group treated with ISDN ointment (n = 105) or a group treated with LIS (n = 102). The same investigators examined the patients in a blinded manner, 1, 2, 3, 6, and 12 months after the treatments.

The anal fissure had healed completely by 4 weeks in 64.7 versus 92.2 %, and by 6 months in 77.1 versus 97.1 % of the ISDN and LIS group patients, respectively. At 12 months, the recurrence rates were 4.8 versus 1 % for the ISDN and LIS groups, respectively, and the success rates of the treatments were 72.4 versus 96.1 %, respectively. Six patients in the LIS group experienced minor fecal incontinence, and seven (6.7 %) patients in the ISDN group experienced headaches that responded well to paracetamol.

ISDN ointment was reported by all patients to be easy to use. Although its success rate was lower than that of surgery, ISDN can be offered to selected patients with a chronic anal fissure, as it has a low recurrence rate and rare side effects are rare.