[STDs] Atlas of Proctitis, Colitis, and Enteritis

Atlas of Proctitis, Colitis, and Enteritis

OVERVIEW

Sexually acquired proctitis can be caused by Neisseria gonorrhoeae, Chlamydia trachomatis, herpes simplex virus (HSV), and Treponema pallidum. Most such infections are acquired by direct exposure through anal intercourse, but some cases in women probably result from anal exposure to infected cervicovaginal secretions, and some infections among men who have sex with men (MSM) may be transmitted by direct exchange of anorectal secretions by fingers or sex toys. Enteritis, or small intestinal infection, can be sexually acquired by practices that foster oral exposure to feces. Giardiasis, salmonellosis, cryptosporidiosis, microsporidiosis, isosporiasis, and norovirus gastroenteritis are examples of sexually transmissible enteric infections. Colitis and proctocolitis are acquired sexually either from fecal–oral contamination, e.g., amebiasis and shigellosis, or by rectal inoculation, e.g., lymphogranuloma venereum (LGV). Campylobacter infection and salmonellosis, acquired orally, may result in enteritis, colitis, or both syndromes (enterocolitis). All sexually active persons are susceptible to these infections, but the practices conducive to their transmission are most frequent among MSM, who comprise the majority of patients with these syndromes. Sexually transmitted enteritis, colitis, and proctocolitis are clinically indistinguishable from similar syndromes acquired nonsexually, such as inflammatory bowel disease and numerous foodborne or waterborne infections. In patients with AIDS, colitis is often caused by cytomegalovirus (CMV) and other opportunistic pathogens.

EPIDEMIOLOGY

Incidence and Prevalence

• Highly variable, depending on sexual practices

• Reliable statistics not available

Transmission

• Receptive anal intercourse

• Sexual practices that risk fecal–oral contamination (e.g., analingus, contaminated hands, or sex toys) 

• Rectal STDs in women probably can be acquired via anal contamination with infected cervicovaginal secretions

• LGV among MSM apparently has been transmitted by direct rectal contamination through hands

and sex toys; the same mechanism probably explains some other rectal STDs in MSM

Age

• No specific predilection

Sex and Sexual Orientation

• Sexually transmitted gastrointestinal STDs are most common in MSM 

HISTORY

Incubation Period

• Variable, depending on specific infection

Symptoms

Proctitis

• Anorectal pain, tenesmus, constipation, bleeding

• Mucus or purulent exudate may be observed during defecation or on feces

• Anal or perianal vesiculopustular lesions or ulcers (suggest herpes or syphilis)

• Fever or systemic symptoms (suggest primary herpes or LGV)

• Sacral neuropathy (e.g., bladder paralysis; suggests primary herpes)

Colitis

• Diarrhea, sometimes bloody

• Abdominal cramps

• Often fever or other systemic symptoms

Enteritis

• Diarrhea, usually without cramping

• Variable degrees of nausea, vomiting, anorexia, bloating, flatulence, weight loss, fever

Proctocolitis and Enterocolitis

• Simultaneous symptoms of the component syndromes

Epidemiologic History

• History of exposure

• Sexual practices that foster anorectal or fecal–oral exposure

PHYSICAL EXAMINATION

Proctitis

• Anoscopy or sigmoidoscopy showing mucosal erythema, extending ≤10 cm above anus

• Purulent exudate, typically observed in anal crypts

• Mucosal ulcers or petechiae

• Bleeding induced by swabbing rectal mucosa (“wipe test”)
• Ulcers or vesiculopustules of anal canal or perianally

Colitis and Proctocolitis

• Abdominal tenderness, usually maximal in left lower quadrant

• Sigmoidoscopy or colonoscopy typically demonstrates inflammation >10 cm above the anus

• Proctocolitis causes clinical signs and mucosal changes consistent with both proctitis and colitis

• Fever is common

Enteritis and Enterocolitis

• Often no physical findings

• Sometimes abdominal tenderness or enhanced bowel sounds

DIFFERENTIAL AND LABORATORY DIAGNOSIS

Proctitis

• Most MSM with acute proctitis have gonorrhea, chlamydial infection (including LGV), herpes, or

primary or secondary syphilis

• Differential diagnosis probably is similar in sexually active women, but poorly studied

• Anoscopy for visual inspection and clinical specimens

° Gram-stained smear of rectal secretions

° NAAT or cultures for N. gonorrhoeae

° NAAT or culture for C. trachomatis

° NAAT or culture for HSV

° Serological test for syphilis

° Type-specific HSV serology

° Darkfield examination if ulcers or other lesions consistent with syphilis observed

° Rectal biopsy if diagnosis remains obscure

Colitis and Proctocolitis

• Usual causes are C. trachomatis (especially LGV strains), Campylobacter jejuni, Shigella species, Salmonella species, and Entamoeba histolytica

• Clinically indistinguishable from ulcerative colitis or Crohn disease

° Perform sigmoidoscopy or colonoscopy

° NAAT or culture for N. gonorrhoeae

° NAAT or culture for C. trachomatis

° NAAT or culture for HSV

• Examine stool for leukocytes, culture for enteric pathogens, and ova and parasite examination

• Chlamydia/LGV serology

• Biopsy if diagnosis remains obscure; LGV may be histologically indistinguishable from Crohn disease 

Enteritis and Enterocolitis

• Broad differential diagnosis

° Among MSM, Giardia lamblia probably is most common cause of enteritis without colitis

° Campylobacter

° Salmonella

° Cryptosporidium, Isospora, Cyclospora, microsporidia, CMV, and Mycobacterium avium complex are potential etiologies in HIV-infected and other immunocompromised persons

• Examine stool for leukocytes

• Stool culture for enteric pathogens

• Ova and parasite examination

• Consider “string test” of duodenal secretions for G. lamblia

• Colonoscopy, upper gastrointestinal endoscopy, and mucosal biopsy often are indicated

TREATMENT

Proctitis and Proctocolitis

• Treat according to specific etiology

• Depending on clinical severity and available epidemiologic information, presumptive therapy may

be indicated while awaiting diagnostic test results:

° Ulcerative proctitis that suggests syphilis or herpes: Benzathine penicillin plus valacyclovir or acyclovir: 

° Proctitis or proctocolitis without mucocutaneous ulceration: Ceftriaxone plus doxycycline for

presumptive chlamydia or gonorrhea 

° Suspected LGV: Doxycycline 100 mg PO bid for 3 weeks 

Colitis and Enterocolitis

Amebiasis

• Overt colitis or other suspicion of invasive amebiasis

° Metronidazole 750 mg PO tid for 10 days

followed by

° Iodoquinol 650 mg PO tid for 3 weeks

• Asymptomatic carriage

° Iodoquinol 650 mg PO tid for 3 weeks

or

° Paromomycin 10 mg/kg body weight tid plus diloxanide furoate 500 mg PO tid for 3 weeks 

Salmonellosis

• Most cases resolve without antimicrobial therapy

• If indicated by severe infection, pending susceptibility test results:

° Ciprofloxacin 500 mg PO bid for 7 days, or

° Other fluoroquinolone regimen in equivalent dosage

Shigellosis

• Most cases resolve without antimicrobial therapy

• If indicated by severe infection, pending susceptibility test results:

° Ciprofloxacin 500 mg PO bid for 7 days, or

° Other fluoroquinolone regimen in equivalent dosage

Campylobacter Infection

• Mild cases usually require no treatment

• Severe infections

° Azithromycin 500 mg PO once daily for 3 days

or

° Erythromycin 500 mg PO qid for 7 days

Enteritis

Giardiasis

• Metronidazole 250–500 mg PO tid for 7 days

or

• Paromomycin 500 mg PO tid for 7–10 days

or

• Furazolidone 100 mg PO qid for 7–10 days 

21–1. a. Gonococcal proctitis: anoscopic view of purulent exudate and mucosal bleeding (positive “wipe test”). b. Gram-stained smear of rectal exudate, showing a single PMN with ICGND. 

CASE 1

Patient Profile Age 34, unemployed, methamphetamine-addicted gay man

History Anal itching, discharge, and blood mixed in stool for 3 days; no diarrhea, cramps, fever, or

systemic symptoms; frequent unprotected sex with anonymous partners

Examination Genitals normal; anus normal; anoscopy showed purulent exudate and mucosal friability with spontaneous bleeding, enhanced by swabbing (positive “wipe test”)

Differential Diagnosis Gonorrhea, herpes, chlamydial infection (including LGV), syphilis

Laboratory Gram stain of rectal exudate showed PMNs, some with ICGND; rectal culture for N. gonorrhoeae (positive); rectal cultures for C. trachomatis and HSV (both negative); darkfield examination, stat RPR, VDRL, HIV serology (all negative)

Diagnosis Gonococcal proctitis

Treatment Cefixime 400 mg PO, single dose, plus azithromycin 1.0 g PO, single dose

Partner Management Patient was unable to identify sex partners

Comment The patient was seen before resurgent LGV appeared in MSM in the 2000s, and before current recommendations of ceftriaxone for gonorrhea. Today work-up for acute proctitis would include NAAT for C. trachomatis and LGV serology, and treatment with ceftriaxone 250 mg IM instead of cefixime (see Chaps. 3 and 4). Although Gram-stained smears of anal secretions are optional, microscopic examination of anoscopically obtained specimens may be useful, especially if purulent  exudate is observed and directly sampled. In this patient, the smear permitted presumptive diagnosis and immediate specific therapy for gonorrhea. The patient’s symptoms resolved over the next 2 days, but he returned 2 weeks later with sore throat, fever, cervical lymphadenopathy, and a faint generalized maculopapular skin rash; primary HIV infection was diagnosed. Had he presented in 2010, HIV serology would have included NAAT for HIV RNA, perhaps permitting diagnosis of his acute HIV infection at the initial visit.

21–2. Acute proctitis due to primary herpes in a man who presented 8 days after receptive anal sex with a new partner, with 5 days of increasing perianal pain, tenesmus, difficulty urinating, fever, and headache. a. Ulcer of perineum anterior to anus, with anal edema and erythema. b. Mucosal ulcers and exudate viewed by fiberoptic sigmoidoscopy. 

21–3. Proctitis due to Chlamydia trachomatis (non–LGV
strain), showing mucosal erythema and edema, viewed by
fiberoptic sigmoidoscopy.  

21–4. Gonococcal proctitis: purulent rectal exudate viewed
by fiberoptic sigmoidoscopy.  

21–5. Amebic proctocolitis: rectal mucosal ulcerations,
exudate, and petechiae due to amebic proctocolitis,
viewed by fiberoptic sigmoidoscopy. Note similarity to
herpetic and gonococcal proctitis 

REFERENCES

H. Hunter Handsfield, MD, Color Atlas & Synopsis of Sexually Transmitted Diseases, Third Edition.