MEDICAL PHYSIOLOGY

Detailed explanation-1: -Hemorrhoids (HEM-uh-roids), also called piles, are swollen veins in your anus and lower rectum, similar to varicose veins. Hemorrhoids can develop inside the rectum (internal hemorrhoids) or under the skin around the anus (external hemorrhoids).

Detailed explanation-2: -Internal hemorrhoids drain through the superior rectal vein into the portal system. External hemorrhoids drain through the inferior rectal vein into the inferior vena cava. Rich anastomoses exist between these two and the middle rectal vein, connecting the portal and systemic circulations.

Detailed explanation-3: -The main warning signs of anal cancer are rectal pain, itching and bleeding, as well as changes in bowel movements, such as unusually narrow stools. Hemorrhoids, which are painful clusters of inflamed veins in the rectum and anus, can produce many of the same symptoms as anal cancer.