What are the diagnostic steps and treatment options for proctitis?

Diagnosing Proctitis

For patients with suspected proctitis, perform anoscopy with Gram stain of anorectal exudate, and test all patients for N. gonorrhoeae, C. trachomatis, T. pallidum, and HSV, while obtaining a detailed sexual history focusing on receptive anal intercourse. 1, 2

Essential Diagnostic Steps

Clinical History and Risk Assessment

• Obtain a detailed sexual history specifically asking about receptive anal intercourse, as this is the primary risk factor for sexually transmitted proctitis 1
• Document symptoms including anorectal pain, tenesmus, rectal discharge, bleeding, and constipation 3, 4
• Assess HIV status in all patients, as this affects both disease severity and treatment approach 1, 2
• Ask about oral-anal contact, which may indicate enteric pathogen exposure 3

Physical Examination and Endoscopy

• Perform anoscopy to visualize the rectal mucosa and identify inflammation limited to the distal 10-12 cm of rectum 3, 2
• Examine a Gram-stained smear of anorectal exudate for polymorphonuclear leukocytes, which indicates acute inflammation requiring empiric treatment 3, 2
• Look for specific findings: bloody discharge, perianal ulcers, or mucosal ulcers suggest LGV and require extended treatment 2

Laboratory Testing

• Test all patients for the four primary sexually transmitted pathogens: N. gonorrhoeae (NAAT or culture), C. trachomatis, T. pallidum, and HSV 1, 2
• If C. trachomatis is positive on rectal swab, perform molecular PCR testing specifically for LGV serovars, as this determines treatment duration 2
• Perform HIV and syphilis testing in all persons with acute proctitis 2
• Consider testing for Mycoplasma genitalium in symptomatic patients after excluding the four primary pathogens 4

Treatment Algorithm

Empiric Treatment

If anorectal pus is present on examination or polymorphonuclear leukocytes are found on Gram stain, initiate empiric treatment immediately with ceftriaxone 250 mg IM single dose PLUS doxycycline 100 mg orally twice daily for 7 days 2

This covers both gonorrhea and chlamydia while awaiting confirmatory testing 3, 2.

LGV-Specific Treatment

For patients presenting with bloody discharge, perianal ulcers, or mucosal ulcers, extend doxycycline treatment to 100 mg twice daily for a total of 3 weeks to adequately treat LGV proctitis 2

The 2021 European guideline notes that LGV proctitis is increasingly found in HIV-negative MSM, making clinical recognition critical 4.

Pathogen-Specific Considerations

• N. gonorrhoeae and C. trachomatis (including LGV serovars) are the most common sexually transmitted pathogens causing proctitis 3, 1, 2
• HSV proctitis can be especially severe in HIV-infected individuals and may require antiviral therapy 3, 1, 2
• T. pallidum can cause proctitis mimicking rectal cancer or IBD, requiring high clinical suspicion 5

Critical Diagnostic Pitfalls

Distinguishing from Inflammatory Bowel Disease

Infectious proctitis frequently mimics IBD both clinically and endoscopically, making sexual history essential 6, 7, 8. Recent case reports demonstrate patients initially worked up for IBD who actually had chlamydial or syphilitic proctitis 7, 5.

The key distinguishing features include:

• Recent onset symptoms in sexually active individuals suggest infection over IBD 6
• Presence of sexually transmitted risk factors (receptive anal intercourse, multiple partners) 1, 7
• Response to antibiotic therapy rather than immunosuppression 5

Partner Management

Partners who had sexual contact within 60 days before symptom onset must be evaluated, tested, and treated presumptively 2, 9

Both patient and partners should abstain from sexual intercourse until treatment completion (7-day regimen) and symptom resolution 2, 9.

Follow-Up Protocol

Retesting Requirements

For proctitis associated with gonorrhea or chlamydia, retest for the respective pathogen 3 months after treatment 2, 9

This detects both treatment failure and reinfection 9.

Persistent Symptoms

Patients with persistent symptoms after treatment require evaluation for reinfection, treatment failure, or alternative diagnoses 1, 9

Consider repeat anoscopy or sigmoidoscopy for those with ongoing symptoms 9.

Special Populations

HIV-positive patients require more vigilant follow-up due to risk of severe disease and opportunistic infections including CMV, which can cause severe proctitis in immunosuppressed patients 3, 1, 9

Additional Considerations

Proctocolitis vs. Enteritis

If symptoms extend beyond the rectum with diarrhea and abdominal cramps, consider proctocolitis from Campylobacter, Shigella, E. histolytica, or LGV serovars 3, 1. Enteritis without proctitis symptoms suggests Giardia lamblia in healthy individuals or opportunistic pathogens in HIV-infected patients 3, 1.

Prevention Counseling

Counsel patients about safer sex practices including consistent condom use for anal intercourse, though condom use does not guarantee complete protection as infections often spread without penile penetration 9, 4