Hemorrhoids are swollen veins in the rectum, anal canal. They are caused by constipation, obesity, and pregnancy. Hemorrhoids can cause bleeding and can be extremely painful when filled with blood clots called Thrombosed Hemorrhoid’s. They can be either external or internal External hemorrhoids can be treated with a minimally invasive procedure called hemorrhoidal banding. It involves placement of band at the base of the hemorrhoid to cut off the blood supply to the hemorrhoid.