A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. XXXI. "Strainodynia": an etiopathologic study.

"Strainodynia" is the name I give to the excessive and exhaustive straining that may accompany defecation. Eighty-six patients with strainodynia were studied; the investigations comprised study of the stool character, proctoscopy, colonoscopy, barium enema, intestinal transit rate, EMG, manometry, and rectal biopsy. These patients were classified into 3 groups: band, diet, and levator strainodynia. The first, band strainodynia, more common in men, presented with a normal stool character. However, the rectal neck pressure was elevated, and a fibrous band could be demonstrated by a rectal neck biopsy. Bandotomy relieved the strainodynia. Diet strainodynia, more common in women, presented with stool frequency and weight less than normal. Rectal neck pressure was normal or elevated, and the rectosphincteric reflex was diminished. There was internal sphincter fibrosis. Improvement occurred after dietary management or internal sphincterotomy. Levator strainodynia was due to levator dysfunction syndrome. Stools were repeatedly obstructed at defecation despite normal stool character. Rectal neck pressure was elevated only on straining. There was reduced levator myoelectric activity. Levatorplasty cured the condition.