Proctitis (Inflamed Rectum) Causes, Symptoms, Treatment

The rectum is the end portion of the large intestine that holds the feces before a bowel movement. Like any part of the large intestine it may become inflamed. This can occur for various reasons, such as infections, injuries or autoimmune diseases that affect the rectal tissue. The inflammation may involve the neighboring sigmoid colon and anal canal.

What is proctitis?

Proctitis is the medical term for inflammation of the rectum, the portion of the large bowel between the sigmoid colon and anus. It may be acute or chronic and can involve the colon and usually extends to the anus. Inflammation of the colon is known as colitis. Inflammation of the anal canal is known as anusitis. Proctitis often occurs with colitis and anusitis.

Although proctitis may arise due to various causes, the concern lies with sexually transmitted infections, especially if there is anal intercourse. In these cases, patients often delay seeking medical treatment due to embarrassment until the symptoms worsen. The infection may become more extensive and complications may arise. Repeated episodes can lead to chronic proctitis.

Acute and Chronic Proctitis

In proctitis, there is inflammation of the rectal mucosa which is the most superficial lining of the rectum. Acute proctitis arises suddenly and usually persists for a short period of time. It is more commonly associated with infections and injury. Depending on the severity, the inflammation may also involve deeper lying tissue of the rectum and damage local blood vessels.

Chronic proctitis or severe acute cases, especially due to infectious causes, that remain untreated may lead to ulceration of the rectum. It may lead to complications like anemia due to chronic bleeding, rectal strictures due to fibrosis (scar tissue) and the development of a fistula (anorectal, rectovaginal, rectovesical). This is generally seen in prolonged and poorly managed cases of proctitis.

Causes of an Inflamed Rectum

The more common causes of proctitis include infections, particularly sexually transmitted infections, and exposure to radiation usually in the treatment of colorectal cancer. The causes of proctitis that can therefore be divided into infectious and non-infectious causes.

Infections Causes

Of the sexually transmitted infections that cause proctitis, gonorrhea, chlamydia and genital herpes caused by the herpes simplex virus (HSV-1, HSV-2) are the more frequently seen infections. It is more likely to occur with anal intercourse, with a higher incidence among homosexual men. Other infections include cytomegalovirus (CMV), Entamoeba histolytica and various pathogens seen with foodborne infections and in infectious colitis. Proctitis is also seen with secondary syphilis and HIV infection.

Non-Infectious Causes

Non-infectious causes of proctitis include inflammatory bowel disease (ulcerative colitis or Crohn’s disease), bowel ischemia, immunodeficiency disorders and radiation exposure.

Radiation

Radiation proctitis is frequently seen in patients receiving radiation therapy for malignancies in the pelvis and lower abdomen. This is a form of electromagnetic injury to the rectum. It is common with radiation therapy for colorectal cancer but may also occur with treatment for prostate cancer or uterine cancer.

Injury

Anal intercourse is one of the possible causes of proctitis. It is more likely to be severe if it occurs due to sexually transmitted infections. Enemas, particularly involving the use of toxic substances, like hydrogen peroxide, may also cause proctitis.

Apart from the chemicals in these enemas that may cause inflammation, there may also be injury caused by the application of the enema. Suppositories are an unlikely cause of proctitis unless there is chemical injury due to the composition of the suppository.

Bowel Diseases

Conditions that affect the colon may also involve the rectum. Inflammatory bowel disease (IBD) is a chronic inflammatory condition that may affect the rectum. The exact cause is unknown but it appears to be autoimmune in nature. This means that the immune system attacks the bowel walls. Apart from inflammation, ulcers can form in the bowel wall.

Ischemic bowel disease, or ischemic colitis, is a consequence of reduced blood flow to the wall of the bowel and may involve the rectum. It occurs when the arteries to the bowel becomes narrowed or blocked thereby reducing blood and oxygen to the bowel wall. This causes tissue injury (ischemia) and inflammation.

Other Causes

A significant number of proctitis cases are idiopathic meaning that is due to unknown causes. Proctitis can also arise in people with a weakened immune system (immune deficiency) who are prone to infections. However, proctitis in these individuals may also occur for non-infectious reasons.

Signs and Symptoms of Proctitis

There are a host of signs and symptoms that may arise with proctitis. These symptoms can vary depending on the cause and severity of the inflammation.

• Rectal bleeding may occur spontaneously but is more commonly observed after a bowel movement. It may be more obvious when wiping after defecation.
• Rectal pain or anal pain which may worsen during defecation. There may also be lower abdominal pain, towards the lower left side if the neighboring colon is affected.
• Mucus in the stool which may also give the feces a sticky feeling.
• Frequent bowel movements or diarrhea with/without watery stool.
• Tenesmus which is a constant urging to pass stool even after a bowel movement.
• Itching of the rectum and anus may also be present.

Treatment of Proctitis

The treatment of proctitis depends on the underlying cause. This may require a colonoscopic investigation of the anal canal, rectum and sigmoid colon. Medication or even surgery may be necessary. However, in some cases supportive measures may be sufficient to treat and manage proctitis until the condition spontaneously resolves.

• Antimicrobials are used for infections which includes antivirals, antibiotics or antiparasitic agents.
• Corticosteroids can help to reduce inflammation.
• Antispasmodic drugs to reduce cramps and discomfort.
• Painkillers to ease pain in the colon, rectum or anus.
• Disease-modifying antirheumatic drugs (DMARD) like sulfasalazine.
• Anti-inflammatory drugs like mesalamine which are used for inflammatory bowel disease.

Supportive Measures

• Sitz baths can help to soothe the anus.
• Stool softeners may be prescribed to prevent the passage of hard, dry stool which can worsen inflammation and exacerbate pain.
• A low residue diet may also be advisable to limit stool volume and frequency of bowel movements.
• High fiber foods and fiber supplements should be minimized if necessary.
• Antidiarrheal agents to stop bowel movements is not advisable unless prescribed by a medical doctor.

References:

1. Acute proctitis. Medscape