Rectal pain with a fever may be caused by an infection.

• A rectal abscess is a bacterial infection with a pocket of pus in the anal area. This type of abscess may occur in a passageway that is connected to the rectum (anal fistula). Certain diseases may increase your risk for a serious infection. People who have diabetes or an impaired immune system require medical treatment at the first signs of infection.
• Infection of the prostate gland (prostatitis) may cause pain that is felt in the rectum. Symptoms of a prostate infection include painful or difficult urination (dysuria) and a cloudy discharge or drip from the tip of the penis.
• Sexually transmitted diseases such as genital herpes, genital warts (human papillomavirus, or HPV), chlamydia, and gonorrhea may infect the rectal area and cause pain and fever.
• Rectal pain and fever also may be seen with ulcerative colitis, Crohn's disease, ischemic bowel disease, perforation from injury, and infected hemorrhoids.

Call your health professional for an evaluation if you have rectal pain and a fever.