This section is from the book "A Manual Of Pathology", by Guthrie McConnell. Also available from Amazon: A Manual Of Pathology.
Stenosis Or Narrowing Of The Lumen sometimes occurs, usually as a result of the contraction of cicatrices formed after ulceration. The primary ulcer may be syphilitic, tuberculous, or rarely typhoidal.
The syphilitic ulcer has its long diameter at right angles to the long axis of the intestine, usually in the rectum just above the sphincter, and is generally completely annular. It is characterized by extensive fibrous tissue formation, which, subsequently contracting, causes stenosis. The tuberculous form lies transverse to the intestine, but does not completely encircle the gut. Constriction may occur as a result. The typhoid ulcer has its long axis parallel to that of the intestine and does not tend to form much fibrous tissue. If there is a cicatrix formed, it usually causes a slight puckering of the intestine, very seldom resulting in stenosis.
Stenosis may result from the presence of a neoplasm within the intestine or from pressure from without.
Dilatation results from incomplete obstruction. Is most marked in the large intestine as a result of retained fecal matter which undergoes decomposition and assists in the dilatation. This condition is usually associated with localized pouches or diverticula. Are most common in the rectum.
Perforation may be due to traumatism or may result from ulceration. If the opening is a small one, it may be filled up by a plug of fibrin and no damage result; if larger, there will be an escape of fecal contents into the peritoneum, with fatal results. If the process of ulceration has been a very slow one, as in tuberculosis, such dense adhesions may have formed as to prevent the escape of fecal contents into the abdominal cavity. Instead of opening within the body the perforation may open out onto the skin surface, giving rise to a fecal fistula.
Rupture may follow injuries of the abdomen or may result from accumulations of gas.