(See also Overview of the Anus and Rectum.)
Proctitis is inflammation of the lining of the rectum (rectal mucosa).
The rectum is the section of the digestive tract above the anus where stool is held before it passes out of the body through the anus.
Proctitis, which is becoming increasingly common, has several causes. It may result from Crohn disease or ulcerative colitis. It can also result from a sexually transmitted disease (such as gonorrhea, syphilis, Chlamydia trachomatis infection, or herpes simplex virus infection), especially among men who have sex with men.
A person whose immune system is impaired is also at increased risk of developing proctitis, particularly from infections by herpes simplex virus or cytomegalovirus.
Proctitis may also be caused by some bacteria not transmitted sexually, such as Salmonella, or by the use of an antibiotic that destroys normal intestinal bacteria, thus allowing other bacteria to grow in their place (Clostridium difficile—see Clostridium difficile-Induced Colitis).
Another cause of proctitis is radiation therapy directed at or near the rectum, which is commonly used to treat prostate and rectal cancer.
To make the diagnosis of proctitis, a doctor looks inside the rectum with a proctoscope or sigmoidoscope (a tube used to view the rectum—see Endoscopy) and takes swabs and a tissue sample of the rectal lining for examination. The laboratory then can identify the bacterium, fungus, or virus that may be causing the proctitis.
Blood tests for syphilis and stool tests for Clostridium difficile are also done.
A doctor may also examine other areas of the intestine using colonoscopy (examination of the entire large intestine with an endoscope) to look for Crohn disease or ulcerative colitis.
Antibiotics are the best treatment for proctitis caused by a specific bacterial infection. When proctitis is caused by use of an antibiotic that destroys normal intestinal bacteria, a doctor may prescribe metronidazole or vancomycin, which should destroy the harmful bacteria that have displaced the normal ones.
When the cause of proctitis is radiation therapy, formalin can be applied directly to the affected area for relief of symptoms. Anti-inflammatory drugs such as hydrocortisone (a corticosteroid) or mesalamine are alternative treatments that may provide relief. Both hydrocortisone and mesalamine can be given as either an enema or a suppository. Some corticosteroids are available in a foam preparation that can be inserted with a cartridge and plunger. Mesalamine and other anti-inflammatory drugs, such as sulfasalazine and olsalazine, may be taken by mouth at the same time that drugs are given rectally, for added benefit. If these forms of treatment do not relieve the inflammation, corticosteroids taken by mouth may be used.
If proctitis has caused bleeding from the lining of the rectum, doctors can use argon plasma, lasers, electrocoagulation, and heater probes to stop the bleeding.