The mucosa is a mucus-secreting (lubricating) membrane that lines the digestive tract, including the colon and the rectum. The rectum is the last stop before stool, what remains after digestion, is excreted. Erythematous mucosa occurs when the mucosa becomes red due to increased blood flow, usually as part of an inflammatory process. The most common type of erythematous mucosa of the rectum, proctitis, can be caused by sexually transmitted diseases, inflammatory bowel diseases, other infections or radiation therapy.

Is This an Emergency?

If you are experiencing serious medical symptoms, seek emergency treatment immediately.

Signs and Symptoms

Signs and symptoms of erythematous mucosa of the rectum or proctitis include a feeling of rectal fullness, urgent and frequent bowel movements, bleeding from the rectum, bloody diarrhea, inability to have a bowel movement, pain in the rectum, pain on the left side of the abdomen, excretion of mucus through the rectum, pain on elimination and a fever lasting more than two days. Typically proctitis symptoms do not worsen over time.

Causes of Erythematous Mucosa of the Rectum

Sexually transmitted diseases such as gonorrhea, genital herpes and chlamydia and infections caused by eating food contaminated with salmonella, shigella and campylobacter can cause proctitis by irritating the lining of the rectum. Crohn’s disease, ulcerative colitis, irritable bowel syndrome, diverticulitis and other inflammatory bowel diseases can also irritate the colon and rectum 2. Radiation therapy for cancer in the area of the rectum can lead to proctitis immediately after treatment or even years later.

Diagnosing Erythematous Mucosa of the Rectum

Initial diagnostic tests will probably include a blood test and stool to look for signs of infection or inflammation. The doctor will also probably perform a colonoscopy, where a lighted scope is inserted into the colon to inspect the lining of the rectum and colon. During the colonoscopy a small sample of mucosal tissue (biopsy) may be removed for further analysis. The doctor may also want an abdominal X-ray or a barium enema X-ray of the colon.


Initially steroids reduce symptoms of irritation in the rectum. Steroids cannot be used for long periods because of the risk of osteoporosis and other side effects. Acetaminophen is useful for pain. Aspirin and other non-steroidal anti-inflammatory drugs (NSAIDS) cannot be taken because they can irritate the already inflamed membranes. Immunomodulating drugs may be prescribed for severe symptoms. These drugs dampen immune system response and calm mucosal irritation. Eliminate foods that make symptoms worse. For severe, unresponsive disease a colostomy or removal of the colon may be necessary.

Living with Erythematous Mucosa of the Rectum

Often there is no cure for this condition. Even if infection is the cause and it is treated successfully, the damage to the mucosal lining may be permanent. Although symptoms tend to flare up periodically rather than remain constant, flare-ups are unpredictable. Counselors and support groups can provide coping skills and emotional reinforcement.