Several diseases and conditions can cause the lining of the rectum to become inflamed (proctitis). They include:

  • Inflammatory bowel disease. About 30 percent of people with inflammatory bowel disease (Crohn's disease or ulcerative colitis) have inflammation of the rectum.
  • Infections. Sexually transmitted infections, spread particularly by people who engage in anal intercourse, can result in proctitis. Sexually transmitted infections that can cause proctitis include gonorrhea, genital herpes and chlamydia. Infectious proctitis is also associated with HIV. Infections associated with foodborne illness, such as salmonella, shigella and campylobacter infections, also can cause proctitis.
  • Radiation therapy for cancer. Radiation therapy directed at your rectum or nearby areas, such as the prostate, can cause inflammation of the lining of your rectum. Radiation proctitis can begin during radiation treatment and last for a few months after treatment. Or it can occur years after treatment.
  • Antibiotics. Sometimes antibiotics used to treat an infection can kill helpful bacteria in the bowels, allowing the harmful Clostridium difficile bacteria to grow in the rectum.
  • Diversion proctitis. Proctitis can occur in people following some types of colon surgery in which the passage of stool is diverted from the rectum.
  • Food protein-induced proctitis. This can occur in infants who drink either cow's milk- or soy-based formula, and in those who are breastfed by mothers who eat dairy products.
  • Eosinophilic proctitis. A form of proctitis caused by accumulation of a kind of white blood cell (eosinophil) in the lining of the rectum that affects only children younger than 2.
June 12, 2015