Sep 11, - An anal abscess is a painful condition in which a collection of pus develops near the anus. Most anal abscesses are a result of infection from. Nov 13, - At first, most people assume the bleeding is caused by hemorrhoids (painful, swollen veins in the anus and rectum that may bleed). They are a benign and fairly common cause of rectal bleeding. Rectal itching. A lump or mass at the anal opening.