In this study 20 patients suffering from chronic constipation due to spastic anal sphincters were operated upon using a new surgical technique. The technique aimed at constructing an active anal dilator mechanism using the obturator internus muscles mobilized from both sides and sutured to the side wall of the anal canal in order to overcome the spastic anal sphincters during defaecation. This series included 3 failures (15%), 16 successful cases (80%), and 1 dissatisfied patient despite normal postoperative investigations (5%). Eleven patients (55%) showed immediate postoperative normalization of their defaecation. Five patients (25%) showed normalization of their defaecation after 10 sessions of electric stimulation of the transposed muscles given 1 month postoperatively for 10 successive days. All the successful cases (16 patients) maintained their good results during the period of follow-up which ranged from 16 to 45 months (average = 30.31 months). For the successful cases, follow-up was from 16 to 42 months (average = 26.72 months). Immediate postoperative complications included 3 cases of wound infection and 2 cases of transient incontinence to gases which responded completely to postoperative Faradic stimulation. No cases of persistent incontinence of any degree were detected among the 20 patients studied. The 3 failures were mainly due to avoidable technical problems. The technique was safe, easy, and physiological, using a strictly perineal approach.