Connective-tissue growths are unusual and generally benign. Fibroma, lipoma, and myxoma are sometimes seen. They may cause some obstruction if large. Sarcoma is rare. It arises within the submucosa and extends very rapidly, elevating the mucosa. Is generally round-cell in character and may with difficulty be distinguished from the lymphatic enlargements, lymphoma, that are present in the intestine in leukemia and Hodgkin's disease.

Epithelial tumors are more common and not infrequently cause death. Adenomata are quite common, and may be diffuse or of a polypoid nature. They originate from the crypts of Lieberkiihn, as a rule. The polypoid form is more common in the rectum and may undergo inflammatory changes as a result of injury by the feces.

Carcinoma is the most common of the intestinal tumors and is usually composed of cylindric cells. It is most frequent at certain sites, as the papilla of the common bile-duct, the ileocecal valve, the hepatic, splenic, or sigmoid flexures, and within the rectum. It is somewhat elevated, its surface rough, irregular, and ulcerated, and it involves the entire lumen of the gut, causing obstruction. Bleeding from the ulcerated surface is quite common. If the connective-tissue stroma predominates the growth is hard and firm; if very cellular, it is soft, whitish, and spongy. These tumors show a marked tendency to undergo mucoid and colloid degenerations, and metastases to the neighboring lymph-nodes, peritoneum and liver are common.

Squamous epithelioma originate at the anus and may involve neighboring structures.

Parasites of both animal and vegetable types are common occupants of the intestine. Of the animal parasites, the round worms, as the Ascaris lumbricoides, Oxyuris vermicularis, Trichiuris trichiura, Anguillula intestinalis and stercoralis, and Eustrongylus gigas; the tape-worms, Taenia solium, T. saginata, T. echinococcus, and Dibothriocephalus latus; and the sucking worms, the Ankylostoma, are found present under various circumstances.

Other and more unusual forms are the Cercomonas, Trichomonas, Balantidium coli, and the Entamoeba coli and hystolytica.

Foreign bodies of innumerable varieties have been swallowed and subsequently found within the intestine. Sometimes dense masses of fecal concretions, enteroliths, are found. These are composed of a nucleus of epithelium, hair, or other foreign bodies, surrounded by dried fecal matter. They may give rise to local irritation. In the lower animals they are of large size, but in man are generally small.

Tympanites or meteorism is a condition of dilatation of the intestine by the presence of a large amount of gas. It may be so severe as to cause a paralysis of the muscular coat with a cessation of peristalsis.