Rectum

Abstract

The rectum develops from endoderm, emerging from the distal tip of the hindgut. The rectum measures 12 to 15 cm. Resting rectal pressure is approximately 10 mm Hg. Internal hemorrhoids cause painless bright-red bleeding. Surgeons evaluate the rectum mainly by performing a digital rectal examination, anoscopy, endorectal US, and MRI to determine the extent of disease. The choice between rubber band ligation and excisional hemorrhoidectomy depends on the location (internal vs external) and degree of internal hemorrhoids. Complications from excisional hemorrhoidectomy may include bleeding, urinary retention, and severe pain.