Physical Examination of Anus, Rectum and Genitals

Abstract

The terminal portion of the digestive tract is composed of the rectum, anal canal and anus. The rectum is a continuation of the sigmoid colon and ends in the anal canal, and its total length is about 12–15 cm. The anal canal is about 3–3.5 cm long. The orifice at the bottom of the anal canal is called anus which is verged by mucosa with increased pigmentation at the perianal skin. The anal canal has internal and external sphincter which form the anal ring. The anal ring is marked by the skin folds. The dentate line is located at 2 cm above the anal ring, which is composed of anal columns. The voids between anal columns are called the anal crypts. The epithelium of anus is squamous epithelium that changes to mucosal epithelium at the level of the dentate line. The dentate line is also the demarcation line of the rectum and anal canal. There are nearly 85% of ano-rectal diseases occurred in this area. The anterior wall of the rectum in the male is adjacent to the prostate, in the female, it is adjacent to the vagina and uterus.