562 THE DIGESTIVE SYSTEM. 



under the impression that the process was cancerous. Lartigau has sug- 

 gested that the peculiarities of this process may be due to infection with 

 an attenuated form of the tubercle bacillus. ' 



THE EECTUM. 



Besides inflammatory changes similar to those already described as oc- 

 curring in the colon, we sometimes find a suppurative inflammation of 

 the connective tissue which surrounds the rectum, either associated with 

 lesions of the mucous membrane or occurring by itself. 



In adults the lower end of the rectum is the part of the intestine 

 which is the most frequent seat of syphilitic ulceration. Most of these 

 ulcers seem to be the result of unnatural coitus, or of infection from 

 specific sores of the vulva ; but some of them seem to be due to the 

 softening of gummy tumors. The gonococcus is an occasional excitant 

 of inflammation of the rectum. 



Strictures of the rectum may be due to tumors, to cicatrices following 

 trauma or inflammation. 2 



Haemorrhoids (Piles). Ectasiae of the hsemorrhoidal veins are of fre- 

 quent occurrence. They are most frequent in adults and are usually due 



FIG. 338. HEMORRHOIDS. 



Section of an external haeinorrhoid consisting of fibrous tissue and dilated vessels. Covered with epithelium 

 except at the upper right portion where it was attached. 



to venous obstruction in cirrhosis, chronic constipation, pelvic tumors, 

 chronic inflammation of the rectum, etc. The enlarged veins may be 

 within or without the sphincter internal or external haemorrhoids. The 

 dilated veins may have thickened walls and may be surrounded by new- 

 formed connective tissue. The projecting mass in external haemorrhoids 

 may consist in part of dilated vessels, in part of fibrous tissue, and is 

 covered by thickened epithelium (Fig. 338). Considerable haemorrhage 



1 For a study and bibl. see Lartigau, Jour. Exp. Mod., vol. vi., 1901, p. 23. 

 ' 2 For bibliography of uon-malignant rectal strictures see Petersen, Jour. Am. Med. 

 Assn., vol. xxxiv., p. 259, 1900. 



