Benign strictures of the rectum.

Congenital Strictures are usually the result of inadequate' union between the proctodoeal invagination and the hind-gut proper. Any degree of obstruction, from stenosis of the anal orifice up to complete atresia of the anal canal, may be present. Imperforate anus may be associated with absence of a portion or the whole of the rectum. Operations upon such cases early in life may be followed by marked stricture formation. Acquired Strictures may be (i) spasmodic, (2) organic. (i) Spasmodic Strictures are uncommon, but undoubted cases of spasm of the sphincter muscles, without any obvious cause, are met with from time to time. Reflex spasm of the sphincters from associated fissure and anal ulceration is quite well known. (2) Varieties of Organic or Fibrous Stricture. Traumatic Stricture may follow accidental wounds of the anal canal or rectum, in which tissue is lost at the time of injury or else due to subsequent sepsis and sloughing. Gun-shot wounds also come under this category. Pressure of the head during labour against the sacral promontory may be followed by sloughing of the rectal wall, with stricture formation.