A 48-year-old man with a longstanding history of chronic constipation complains of anal itching and discomfort toward the end of the day. He describes a perianal pain when sitting and finds himself sitting sideways to avoid discomfort. Physical examination reveals painful varicose dilations in the anal region, associated with edema. Which of the following is the most likely diagnosis?

Hemorrhoids are dilations of veins of the rectum and anal canal, which may occur inside or outside the anal sphincter. This condition may be aggravated by constipation and pregnancy and can also result from venous obstruction by rectal tumors. Thrombosis of hemorrhoids is exquisitely painful. Of interest, internal hemorrhoids typically bleed without pain, whereas external hemorrhoids typically hurt but do not bleed. The other choices do not feature dilated veins.Diagnosis: Hemorrhoids, varicose veins