Initial Management of Tenesmus
The initial approach to tenesmus requires obtaining a detailed sexual history, performing anoscopy to visualize the rectal mucosa, and testing for sexually transmitted infections (N. gonorrhoeae, C. trachomatis, T. pallidum, HSV) while simultaneously evaluating for inflammatory bowel disease and malignancy. 1, 2
Immediate Diagnostic Evaluation
History and Physical Examination
- Obtain a detailed sexual history to identify risk factors for sexually transmitted proctitis, as this is a common and treatable cause that is frequently missed 1, 2
- Assess for HIV status, as this dramatically affects disease severity and treatment approach 2
- Document associated symptoms: bloody diarrhea, urgency, rectal discharge, fever, abdominal pain, and fecal incontinence 2
- Determine timing: acute onset (infectious) versus chronic/progressive (inflammatory bowel disease or malignancy) 3, 2
Anoscopy and Testing
- Perform anoscopy to visualize rectal mucosa and identify inflammation limited to the distal 10-12 cm, which suggests infectious proctitis 1
- Test all patients for N. gonorrhoeae, C. trachomatis, T. pallidum, and HSV using NAAT or culture 1
- Perform HIV and syphilis testing in all persons with acute proctitis 1
- If anorectal pus is present or polymorphonuclear leukocytes are found on Gram stain, obtain specimens for bacterial culture 1
Empiric Treatment for Infectious Proctitis
When to Treat Immediately
If anorectal pus is present or polymorphonuclear leukocytes are found on Gram stain, initiate ceftriaxone 250 mg IM single dose PLUS doxycycline 100 mg orally twice daily for 7 days before culture results return 1
Bacterial Dysentery
- For ill patients with fever, abdominal pain, bloody diarrhea, and presumptive Shigella infection, initiate empiric fluoroquinolone or azithromycin 1
- Avoid antimicrobial therapy for STEC O157 and other STEC producing Shiga toxin 2, as this worsens outcomes 1
Partner Management
- Partners who had sexual contact within 60 days before symptom onset must be evaluated, tested, and treated presumptively 1
Evaluation for Non-Infectious Causes
Inflammatory Bowel Disease
- Consider ulcerative colitis or ulcerative proctitis, particularly if tenesmus is accompanied by bloody diarrhea, urgency, and colicky abdominal pain 2
- Up to one-third of patients with ulcerative proctitis experience constipation alongside tenesmus 2
- In patients with prior ileal pouch-anal anastomosis, consider pouchitis, which develops in up to 50% within 10 years and presents with tenesmus, increased stool frequency, incontinence, and bleeding 3, 2
Imaging When Indicated
- In most patients with proctitis, imaging is not required 3
- If complex disease is clinically suspected (abscess, fistula, extensive inflammation, or malignancy), CT enterography with IV contrast provides 90% sensitivity for detecting inflammation, peripouch complications, and abscesses 3
- MRI pelvis with IV contrast is superior to non-contrast imaging for visualizing fistula tracts and collapsed tracts without fluid 3
Malignancy Screening
- Approximately 11% of colovesical and colovaginal fistulae are caused by malignancy 2
- Look for soft tissue mass or malignant-appearing lymphadenopathy on imaging, as missing malignancy leads to delayed diagnosis 2
Critical Pitfalls to Avoid
- Failing to obtain detailed sexual history leads to missing sexually transmitted causes 2
- Not assessing HIV status can result in underestimating disease severity, particularly with herpes proctitis and CMV proctitis in immunosuppressed patients 2
- Assuming all tenesmus in inflammatory bowel disease patients represents active colitis can lead to overlooking pouchitis, cuffitis, or irritable pouch syndrome 2
- Overlooking medication-induced causes, particularly NSAIDs, which can exacerbate ulcerative colitis 2
- Avoiding antibiotics in STEC infections is critical, as treatment worsens outcomes 1
When Imaging Is Not Initially Required
Most patients with proctitis do not require imaging initially 3. Imaging should be reserved for: