Usefulness of lateral internal sphincterotomy combined with hemorrhoidectomy by the Milligan-Morgan's technique: results of a prospective randomized trial

Pain is invariably experienced after haemorrhoidectomy. Internal anal spasm is considered to be a major factor in the genesis of such pain. This prospective randomized study was designed to compare the effectiveness of two manoeuvres (surgical sphincterotomy and chemical sphincterotomy) in reducing post-haemorrhoidectomy pain. Sixty patients (38 males, 22 females) with grade III and IV haemorrhoids were included in this study. In all cases resting anal pressure was reported in the range of 50-100 mm Hg. Group A patients underwent Milligan-Morgan haemorrhoidectomy plus chemical sphincterotomy; group B patients underwent Milligan-Morgan haemorrhoidectomy plus internal left lateral sphincterotomy (0.8-1 cm in length) and group C patients underwent Milligan-Morgan haemorrhoidectomy alone. The postoperative course was carefully evaluated and was found to be better in group B. None of the patients treated by surgical sphincterotomy developed incontinence. Two patients in group C developed anal strictures. When indicated, internal left lateral sphincterotomy (0.8-1 cm) is a safe procedure and reduces post-haemorrhoidectomy pain and stenosis.