Separate sections of the intestine demand special attention, inasmuch as not only many diseases occur more frequently at one part than at another, and are subject to numerous modifications in reference to their issue and result, but as many diseases exclusively affect one portion of the intestine. We shall consider the diseases of the duodenum, of the caecum and vermicular process, and of the rectum, separately, on account of their peculiar importance.

A. Diseases Of The Duodenum

We frequently meet with cellular adhesions between the upper transverse portion of the duodenum and the concave surface of the liver and the gall-bladder.

The mucous membrane of the duodenum not unfrequently bulges out through the muscular coat in the shape of a hernial diverticulum, an occurrence which is undoubtedly favored by the absence of the peritoneal investment.

Catarrhal irritation, and even inflammation, undoubtedly often affect the duodenal mucous membrane, and are frequently induced by an anomalous condition of the bile. It appears that they may extend to the biliary ducts, and induce icteric symptoms by a retention of the bile (Stokes). We often find evidence of chronic catarrh or blennorrhoea of the mucous membrane in the dead subject, accompanied by brownish-red or slate-gray discoloration, by hypertrophy of the mucous membrane and Brunner's glands, and by the formation of polypi.

As regards ulcerative processes, we find, besides tubercular ulcer, which is very rare, the perforating ulcer occurring at the upper transverse portion (vide perforating gastric ulcer), and perforation resulting from an extension of the process from the gall-bladder to the duodenum.

Carcinoma very seldom occurs in any shape as a primary affection of the duodenum; it is sometimes secondarily attacked posteriorly by an extension of the disease from the cancerous lymphatic glands surrounding the head of the pancreas and the gall-ducts.