Proctitis & Other Sexually Transmitted Intestinal Syndromes
- • A thorough sexual history, including information about the practice of rectal sex (receptive or insertive) or oral-anal sex, with or without condoms.
- • Screening for rectal pathogens based on sexual risk history.
- • Anoscopy in patients with symptoms of anorectal pain, tenesmus, or discharge.
- • Collection of specimens for gonorrhea, chlamydia, and serologic tests for syphilis and HIV, and stool specimens for culture and ova and parasite examinations in patients with symptoms of proctocolitis.
Proctitis is an inflammatory condition of the rectum that usually occurs secondary to infection introduced during sexual activity. A more extensive condition—proctocolitis—may occur after oral ingestion of a pathogen that produces colorectal inflammation. Both conditions are noted more frequently in men who have sex with men (MSM). Proctitis is commonly caused by gonorrhea, chlamydia, and herpes simplex virus (HSV) infections, and proctocolitis by enteric bacteria or parasites.
The incidence of acute, sexually transmitted proctitis and proctocolitis, which decreased dramatically during the 1980s and early 1990s, began increasing again in the mid-1990s. As a consequence of successful antiretroviral therapy for HIV infection and AIDS, declining concern about HIV and AIDS, and renewed physical health, many HIV-infected men in the United States have increasingly been engaging in sexual risk behaviors associated with the spread of STDs. Consistent condom use between HIV-infected sex partners in some cities has also declined, resulting in substantial increases in rates of syphilis and rectal STDs.
Sexually transmitted intestinal infections may be transmitted by direct rectal inoculation or indirectly in the course of oral-anal contact. Conventional sexually transmitted diseases (STDs) most often cause rectal infections through direct inoculation by anal intercourse, although perineal contamination by cervicovaginal secretions among women has been described. Chlamydia trachomatis and Neisseria gonorrhoeae infect columnar epithelium and infect the anorectal mucosa via oral-genital and rectal insertive intercourse. HSV, human papillomavirus, and Treponema pallidum infect stratified squamous epithelium and can be transmitted similarly to the anorectal region. Although not considered “classical” STDs, enteric pathogens, parasites, and hepatitis A and B can be transmitted during direct oral-anal contact, (anilingus) or during oral-genital contact after rectal intercourse. Exposure to as few as 10–100 organisms of Shigella, Entamoeba histolytica cysts, or Giardia lamblia cysts may precipitate infection.
Multiple partners, anonymous partners, and individual sexual practices that increase the risk of acquiring specific diseases are associated with increased risk of acquiring any STD. Individuals who engage in receptive anal intercourse or anilingus are at high risk for acquiring sexually transmitted proctitis and enteritis.
Anal intercourse continues as a prevalent sexual practice in both homosexual and heterosexual populations. Studies report that up to 43% of adult women have participated in anal intercourse. Teen definitions of sexual activity may not include oral or anal sex, and the prevalence of anal sex among teens engaging in abstinence-only programs is unknown. Clinicians, social workers, and disease intervention specialists must develop a tactful approach for eliciting information regarding anorectal sexual exposure and other high-risk behaviors, because this information may result in more rapid disease detection, treatment, and control.
Because the incidence of acute sexually transmitted rectal and gastrointestinal syndromes is increasing, the diligence of clinicians in counseling patients regarding safer sex practices should not lessen. All patients, regardless of their sexual preferences, should have a careful history to elicit information about gender of sex partners, specific sexual practices, and the method and frequency of condom or other barrier use. This will provide important clues to direct proper evaluation, specimen collection, therapeutic choices, and counseling regardless of patients’ presenting symptoms. Consistent condom use and handwashing using soap and water have been recommended to reduce the transmission of gastrointestinal infections. Although latex barriers are also recommended during oral-anal sex, few persons in practice use that barrier method. Vaccination against hepatitis A is an effective preventive measure, particularly in persons who engage in anal or oral-anal sex. Sexually active persons should be informed about these measures, evaluated to determine the need for hepatitis A vaccination, and offered vaccination, if deemed susceptible.
Several pathogens are associated with sexually transmitted intestinal syndromes (see Table 9–1). Symptoms and clinical manifestations vary, depending on the pathogen involved and the location of the infection. The latter half of this chapter discusses symptoms and signs, laboratory findings, and treatment for common pathogens that can cause proctitis and proctocolitis.
| Proctitis | Proctocolitis | |
|---|---|---|
| Symptoms | Rectal pain, discharge, tenesmus | Symptoms of proctitis, along with cramps and diarrhea |
| Pathogen | Neisseria gonorrhoeae Chlamydia trachomatis Treponema pallidum herpes simplex virus | Entamoeba histolytica Shigella flexneri C trachomatis (lymphogranuloma venereum) Giardia lamblia Salmonella spp |
| Mode of acquisition | Receptive anal intercourse | Direct or indirect fecal-oral contact |
| Anoscopic findings | Rectal exudate + friability | Rectal exudate, friability that may extend into sigmoid colon |
Polymicrobial infection often occurs and can cause upper intestinal and perianal symptoms. Nonetheless, asymptomatic infections are prevalent, and the clinician should routinely inquire about rectal exposure regardless of the patient’s sexual preferences, so as to perform screening tests or anoscopic evaluation when appropriate.
Inflammation involving the rectal mucosa is termed proctitis. The perianal area up to the anal verge is composed of keratinized, stratified squamous dermal epithelium. Lesions caused by syphilis, HSV, or condylomata acuminata, therefore, generally have the same appearance as they do in other genital areas. The stratified squamous epithelium gradually changes to stratified cuboidal epithelium from the anal verge up to the anorectal (pectinate or dentate) line. Infection in this area with an extensive network of sensory nerve endings may be painful, sometimes resulting in constipation or tenesmus as a result of anal sphincter muscle spasm. Above the anorectal line, the rectum is lined by columnar epithelium, and infections of this region that spare the anus are relatively painless. Anorectal sexually transmitted infections, therefore, may be asymptomatic. Symptoms of proctitis, however, include anorectal pain, mucopurulent or bloody rectal discharge, tenesmus, and constipation.
Infections that involve the rectum and the colon are termed proctocolitis. Symptoms may include those of proctitis as well as abdominal pain, bloating, cramping, and sometimes diarrhea and fever.
In order to classify patients into syndromes to direct diagnostic and therapeutic choices, a thorough physical examination is essential. Careful inspection of the perianal region may detect lesions or masses that can be tested for pathogens such as HSV or sampled for darkfield examination. Anoscopy may reveal rectal exudates or rectal bleeding. If the patient has proctitis, sigmoidoscopy often reveals disease limited to the rectum, whereas with proctocolitis, the disease process extends above 15 cm, into the sigmoid colon.
The differential diagnosis of infectious proctitis includes gonorrhea, chlamydia (including lymphogranuloma venereum subtypes), HSV, and, rarely, syphilis. Further discussion of each of these infectious causes is provided later in this chapter. Noninfectious causes include inflammatory bowel disease and neoplastic disease (anorectal cancer). Infectious proctocolitis may be caused by extension of proctitis or other enteric bacterial pathogens (eg, Shigella or Salmonella species) or by parasites such as Entamoeba and Giardia lamblia. Other potential bacterial causes of proctocolitis, such as Campylobacter, Yersinia, and the various E coli species, are beyond the scope of this chapter.
Although most infectious causes of sexually transmitted intestinal syndromes respond readily to treatment, untreated proctitis or proctocolitis may persist and lead to abscesses, fistulae, and strictures. In the preantibiotic era, chronic infection sometimes led to rectal strictures and rectal obstruction that required surgical intervention. Rectal infections substantially increase the risk of HIV acquisition, because the inflamed rectal mucosa is rich with immunologic target cells and defects in the epithelial barrier provide an opening for viral entry.
If the diagnosis is uncertain or treatment fails to resolve the patient’s symptoms, further evaluation, including sigmoidoscopy or colonoscopy and biopsy, may be required. Radiologic imaging (eg, radiographs, computed tomography scan, and magnetic resonance imaging) has a limited role in the management of proctitis and proctocolitis, except to rule out toxic megacolon, which is usually associated with Clostridium difficile colitis.
