Rectal discharge can occur for many reasons, including anal fissure, anal fistula (an abnormal connection between two organs) or abscess
, other infections including sexually transmitted diseases, or chronic inflammatory diseases.
An anal fissure is a small tear in the lining of the anal canal. An anal abscess is an infected, pus-filled cavity. An anal fistula, which is an abnormal connection between the anus and surrounding tissues, can develop from an anal abscess if the infection spreads.