The encephaloid variety is prone to very sudden and rapid breaking down, and may destroy life within a few months. If the finger be passed into the bowel in a case of encephaloid degeneration, it will encounter a large soft tumor occluding the gut: this is a very different sensation from that imparted to the finger in a case of epithelioma or scirrhus. In the former there will be felt a crepitating, as though due to the giving way of a moist, friable substance; in the latter the touch will perceive dense, irregular nodulations and ragged ulcerations having very firm margins.
The rectum may also be involved and destroyed by any of these neoplasms in neighboring organs. A middle-aged woman who was admitted to the Pennsylvania Hospital in a very advanced stage of epithelioma of the cervix uteri died from hemorrhage from the rectum and uterus in eight minutes. At the autopsy it was found that the disease had almost separated the cervix from the body of the uterus, had involved the cul-de-sac of Douglas, and had eroded a large opening into the rectum. Numerous ends of large vessels were observed which had undergone erosion.
Carcinoma of distant organs does not seem to frequently involve the rectum by secondary deposition. "In 160 cases of gastric cancer examined at the Pathological Institution in Prague, Dittrich found secondary cancer of the rectum only twice."20
20 Leube, Ziemssen's Cyclopæd., vol. vii. p. 235.
In these cases of carcinomatous disease originating in the bowel the neighboring lymphatic glands are indurated and enlarged, and secondary deposition in neighboring and distant organs is the rule.
The lower portion of the intestinal tract may become involved in disease by direct extension from the colon, as in dysentery following enteritis or entero-colitis. Habersham says that diarrhoea arises generally from an irritated condition of the large intestine, catarrhal and mucous diarrhoea from slight inflammatory disease closely allied to ordinary coryza affecting the mucous membrane of the large intestine. "In the diarrhoea of soldiers the lesions of the large intestine have been either those of congestion with varying degree of extravasation or of ulceration more or less extensive. The colon in the former cases has invariably presented patches of intense congestion, and in numerous instances extravasation, the amount and intensity varying in different subjects, in a few the whole mucous surface of the intestine having a livid red color; in others tracts of more or less intense congestion at irregular intervals, as in the small intestines, would be noticed. The ileo-cæcal valve almost invariably presented intense congestion. The rectum has uniformly presented intense congestion, with more or less fibrinous exudation. Frequently the presence of fibrinous exudation was a question of doubt."21 The entero-colitis or ordinary summer complaint of infants not infrequently causes a very troublesome form of proctitis. Besides the ordinary causes of dysentery, Feyrer22 states that it is caused by irritation of the solar plexus of nerves, also by the inhalation of sewer emanations and by the ingestion of impure water.
21 Med. and Surg. History of the War of the Rebellion, vol. ii. p. 102.
22 Times and Gazette, 1881, p. 87.
"In dysentery the anus becomes bluish-red, and is even marked with cracks and rents; it is painful to the touch and tightly contracted. In the later stages of severe cases it becomes large and gaping; then the stools are generally discharged unconsciously, and the pain is slight, paralysis of the sphincter ani having occurred. These symptoms indicate generally that death is to be expected. In some of these cases the pathological lesions are limited to the rectum. Dysentery may succeed typhoid fever."23
23 Heubner, Ziemssen, vol. i. p. 552.