Randomized controlled trial of lateral internal sphincterotomy with haemorrhoidectomy.

A prospective trial was conducted to compare haemorrhoidectomy alone (control, group 1) with haemorrhoidectomy plus lateral internal sphincterotomy (group 2) for prolapsed piles. Some 33 patients (18 men, 15 women) of mean(s.e.m.) age 40(2.3) years were randomized, 16 to group 1 and 17 to group 2. There were no significant differences in postoperative pain scores. Mean resting and maximum anal squeeze pressures, studied 6 weeks and 3 months after operation, were generally lower in group 2, but were not significantly different. Two patients in group 2 were distressed by incontinence to liquid faeces which persisted in one after 1 year. There were no other complications in either group after a mean(s.e.m.) follow-up of 11(0.4) months. The addition of lateral internal sphincterotomy to routine haemorrhoidectomy is unnecessary and carries the added risk of incontinence.