Proctitis is inflammation of the lining of the rectum, the last several inches of the large intestine. It can be short-lived or chronic, and the causes range from sexually transmitted infections to inflammatory bowel disease to radiation therapy. The hallmark symptoms are a persistent urge to have a bowel movement, rectal bleeding, and mucus or pus in the stool.
Types and Causes
There are four main categories of proctitis, each with a different underlying trigger.
Inflammatory bowel disease (IBD). Ulcerative colitis is the most common IBD-related cause. It always starts in the rectum and spreads upward in a continuous line through the colon. When inflammation is limited to just the rectum, it’s often called ulcerative proctitis. Crohn’s disease can also affect the rectum, though it tends to skip around the digestive tract and is more likely to cause problems in the area around the anus, including fissures and abnormal tunnels between tissues called fistulas.
Infectious proctitis. Sexually transmitted infections are a leading cause, particularly among people who have receptive anal sex. Chlamydia, gonorrhea, and herpes are the most common culprits. A specific aggressive strain of chlamydia can cause a condition called LGV, which tends to produce severe symptoms including rectal ulcers, heavy discharge, and bleeding. People living with HIV are more likely to develop infectious proctitis and may have more pronounced symptoms.
Radiation proctitis. Radiation therapy targeting the pelvic area, often for prostate, cervical, or rectal cancers, can inflame the rectal lining. This typically develops during treatment and resolves within several weeks after radiation ends. A small percentage of people develop a chronic form that persists long afterward.
Diversion proctitis. This occurs in people who have had surgery to reroute stool away from the rectum, such as a colostomy or ileostomy. Without stool passing through, the rectum loses the short-chain fatty acids and other nutrients that normally keep its lining healthy. The unused tissue becomes inflamed.
Common Symptoms
The most recognizable symptom is tenesmus: a constant feeling that you need to have a bowel movement, even when your bowel is empty. It can feel like cramping or pressure in the rectum that doesn’t go away after using the bathroom.
Other common symptoms include passing blood with your stool, rectal bleeding between bowel movements, and mucus or pus in your stool. Chronic proctitis can also bring diarrhea, urgency, pelvic pain, and in some cases fecal incontinence. Infectious proctitis often adds anorectal pain and visible discharge.
Symptoms overlap significantly between the different types, which is why identifying the underlying cause matters more than treating the symptoms alone.
How Proctitis Is Diagnosed
Diagnosis usually starts with your medical history and a physical exam, then moves to targeted testing to pin down the cause.
- Stool tests can reveal signs of infection. You’ll collect a sample at home and send it to a lab.
- Rectal cultures involve a cotton swab inside the rectum to check for bacteria and other organisms, particularly STI-related pathogens.
- Endoscopy gives the most detailed picture. A doctor threads a thin, flexible tube with a camera into the rectum and colon to view the lining directly. During this procedure, they can take small tissue samples (biopsies) for a pathologist to examine under a microscope.
Endoscopy is especially important when IBD is suspected, since the pattern and depth of inflammation help distinguish ulcerative colitis from Crohn’s disease. For suspected infectious proctitis, rectal swabs tested for chlamydia, gonorrhea, and herpes are standard.
Treatment by Type
Treatment depends entirely on what’s causing the inflammation.
For IBD-related proctitis, the first-line approach is typically a topical anti-inflammatory medication applied directly to the rectum, either as a suppository or an enema. Treatment courses generally run three to six weeks. The goal is to calm the inflammation locally, which tends to produce fewer side effects than oral medications. If topical treatment isn’t enough, doctors may add oral medications or steroid-based options.
Infectious proctitis is treated with antibiotics or antiviral medications matched to the specific organism. Chlamydia-related proctitis, for instance, requires an extended course of antibiotics lasting up to three weeks when severe symptoms like ulcers, bloody discharge, or tenesmus are present.
Radiation proctitis that develops during treatment is often managed with topical pain medications while waiting for it to resolve on its own after radiation ends. Chronic radiation proctitis may need more targeted interventions.
Diversion proctitis is sometimes treated with short-chain fatty acid enemas to replace the nutrients the rectum is no longer getting. In some cases, reconnecting the bowel surgically resolves the problem entirely.
Long-Term Complications
When proctitis is caught early and the cause is treated, most people recover fully. Left untreated or poorly controlled, chronic proctitis can lead to more serious problems. Persistent rectal bleeding over months or years can cause anemia. Ongoing inflammation can produce scar tissue that narrows the rectal passage (a stricture), making bowel movements difficult and painful. In IBD-related cases, fistulas, which are abnormal connections between the rectum and nearby tissues, can develop.
In cases where symptoms are severe and don’t respond to intensive treatment, or when complications like strictures, fistulas, or uncontrolled bleeding develop, surgical options including removal of part or all of the rectum may be considered. This is uncommon and typically a last resort.
Diet During Flares
If your proctitis is linked to IBD, what you eat during a flare can affect how you feel day to day. Many people instinctively avoid high-fiber foods like raw fruits, cruciferous vegetables, and legumes during active symptoms, and this can help with short-term comfort. Historically, clinicians broadly recommended low-fiber diets for IBD patients, but current expert guidelines are moving away from blanket fiber restriction, since fiber plays an important role in long-term gut health.
About 40% of people with IBD in remission also experience overlapping irritable bowel symptoms. For them, reducing fermentable carbohydrates (sometimes called FODMAPs), which include certain fruits, dairy products, wheat, and sweeteners, can help manage bloating, gas, and cramping. During an active flare, softer, easily digestible foods tend to be better tolerated, but long-term dietary changes are best guided by a gastroenterologist or dietitian familiar with your specific situation.