What is Proctocolitis?
Proctocolitis is inflammation of the colonic mucosa extending up to 12 cm above the anus, characterized by symptoms of proctitis (anorectal pain, tenesmus, rectal discharge) plus diarrhea and/or abdominal cramps. 1, 2
Key Distinguishing Features
Proctocolitis differs from isolated proctitis in both anatomic extent and symptomatology:
- Proctitis involves only the distal 10-12 cm of the rectum with symptoms limited to anorectal pain, tenesmus, and rectal discharge 1
- Proctocolitis extends inflammation beyond the rectum to involve the colonic mucosa up to 12 cm above the anus, adding diarrhea and abdominal cramping to the symptom complex 1, 2
- Fecal leukocytes are frequently detected on stool examination in proctocolitis, depending on the causative pathogen 1
Etiologic Categories
Sexually Transmitted Proctocolitis
The most common sexually transmitted pathogens causing proctocolitis include:
- Campylobacter species and Shigella species are frequent causes, particularly in men who have sex with men 1, 3
- Lymphogranuloma venereum (LGV) serovars of Chlamydia trachomatis cause severe proctocolitis in individuals engaging in receptive anal intercourse 1, 2
- Entamoeba histolytica can cause proctocolitis through oral-anal contact 1, 3
- Cytomegalovirus (CMV) or other opportunistic agents are implicated in immunosuppressed HIV-infected patients 1, 2
Inflammatory Bowel Disease-Related Proctocolitis
- In ulcerative colitis, proctocolitis represents disease extending from the rectum proximally but remaining in the left colon 1
- This is classified as "left-sided colitis" when inflammation extends beyond the rectum but remains distal to the splenic flexure 1
- Disease extent influences treatment modality, with topical enemas typically used as first-line therapy for left-sided colitis 1
Transmission Routes
Proctocolitis can be acquired through receptive anal intercourse or oral-anal contact, depending on the specific pathogen involved. 1
- Bacterial pathogens (Campylobacter, Shigella) are transmitted through both routes 1
- LGV serovars require receptive anal intercourse for transmission 1, 2
- Parasitic infections (Entamoeba histolytica, Giardia lamblia) are associated with oral-anal contact 1, 3
Clinical Implications
Diagnostic Approach
Evaluation requires sigmoidoscopy to visualize the extent of mucosal inflammation, stool examination for fecal leukocytes and enteric pathogens, and a detailed sexual history. 2, 3
- Anoscopy alone is insufficient as it cannot assess the proximal extent of inflammation beyond the rectum 1, 2
- HIV status assessment is essential, as it affects both the causative organisms and treatment approach 2, 3
- All patients should be tested for N. gonorrhoeae, C. trachomatis, HSV, and T. pallidum 3, 4
Treatment Considerations
The CDC recommends empirical treatment with ceftriaxone 250 mg IM plus doxycycline 100 mg orally twice daily for 7 days while awaiting diagnostic results. 2, 4
- This regimen covers gonorrhea, chlamydia (including LGV), and syphilis 2
- For confirmed LGV with bloody discharge or mucosal ulcers, extend doxycycline to 3 weeks total 4
- In HIV-infected patients, herpes proctocolitis can be particularly severe and requires specific antiviral therapy 2, 3
Common Pitfalls
- Failing to obtain a sexual history leads to missed diagnoses of sexually transmitted proctocolitis, resulting in inappropriate IBD treatment 5, 6
- Assuming all proctocolitis in young patients is IBD without excluding infectious causes can lead to unnecessary immunosuppression 6
- Not assessing HIV status misses a critical factor affecting both pathogen spectrum and disease severity 2, 3
- Inadequate partner notification and treatment perpetuates transmission and leads to reinfection 4