What is the management for tenesmus?

Management of Tenesmus

The management of tenesmus depends critically on the underlying etiology: for infectious proctitis with acute inflammation, initiate immediate empiric antibiotic therapy with ceftriaxone 250 mg IM plus doxycycline 100 mg twice daily; for radiation-induced tenesmus, argon plasma coagulation is the preferred endoscopic approach; and for malignancy-related tenesmus refractory to opioids, consider tricyclic antidepressants or antiarrhythmic drugs as first-line adjunctive therapy.

Infectious Causes: Sexually Transmitted Proctitis

Initial Assessment and Diagnosis

• Obtain a detailed sexual history specifically asking about receptive anal intercourse and oral-anal contact, as these are primary risk factors for infectious proctitis 1
• Perform anoscopy to visualize rectal mucosa and identify inflammation limited to the distal 10-12 cm 1
• Examine Gram-stained smear of anorectal exudate for polymorphonuclear leukocytes, which indicates acute inflammation requiring immediate empiric treatment 1
• Look for bloody discharge, perianal ulcers, or mucosal ulcers, as these suggest lymphogranuloma venereum (LGV) requiring extended treatment 1

Laboratory Testing

• Test all patients for N. gonorrhoeae, C. trachomatis, T. pallidum, and HSV using NAAT or culture 1
• If C. trachomatis is positive, perform molecular PCR testing specifically for LGV serovars to determine treatment duration 1
• Perform HIV and syphilis testing in all persons with acute proctitis 1

Empiric Treatment Algorithm

• 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 1
• If bloody discharge, perianal ulcers, or mucosal ulcers are present: Extend doxycycline to 100 mg twice daily for 3 weeks total to adequately treat LGV proctitis 1
• Partners who had sexual contact within 60 days before symptom onset must be evaluated, tested, and treated presumptively 1

Follow-Up

• Retest for gonorrhea or chlamydia 3 months after treatment to detect treatment failure and reinfection 1
• HIV-positive patients require more vigilant follow-up due to risk of severe disease and opportunistic infections including CMV 1

Inflammatory Bowel Disease and Radiation Proctitis

Endoscopic Thermal Therapy

• Argon plasma coagulation is the preferred modality for radiation-induced proctitis causing tenesmus and bleeding, as it is a noncontact technique with limited depth of coagulation (2-3 mm) 2
• Multiple treatment sessions are typically required to achieve control of bleeding and symptoms 2
• Short-term complications include anorectal pain, tenesmus, and abdominal distention; long-term complications include chronic rectal ulcer and rectal stricture 2
• Alternative thermal modalities include heater probe or bipolar electrocoagulation, which have shown statistically significant decreases in severe bleeding with improvement in tenesmus at 6-month follow-up 2

Malignancy-Related Tenesmus

Pharmacologic Management for Opioid-Refractory Cases

Tricyclic Antidepressants (First-Line Adjunctive Therapy):

• Nortriptyline 25 mg daily has a 90% response rate for tenesmus in rectal prolapse and malignancy 3
• Desipramine 25 mg daily has a 100% response rate 3
• Amitriptyline 10 mg daily has a 62.5% response rate 3
• TCAs address the rectal hypersensitivity component and break the vicious circle of straining 3
• Response typically occurs within 9 months of treatment initiation 3

Antiarrhythmic Drugs (Alternative Adjunctive Therapy):

• Mexiletine hydrochloride (Mexitil) 150 mg orally in 3 divided doses for pelvic tumor-related tenesmus attributed to neurological dysfunction 4
• Continuous infusion of intravenous lidocaine 2% (Xylocaine) 500 mg/day as an alternative 4
• All patients in case series experienced palliation of symptoms without adverse reactions 4

Opioid Rotation:

• Methadone is effective for tenesmus unresponsive to morphine escalation, as it is lipophilic and exerts lesser activity on gastrointestinal opioid receptors 5
• Consider methadone rotation when morphine and ketorolac fail to control rectal-perineal pain 5

Burst Ketamine (For Severe Refractory Cases):

• Continuous subcutaneous infusion of ketamine over 7 days, combined with midazolam and dexamethasone, can decrease pain scores and reduce opioid requirements 6
• Ketamine antagonizes N-methyl D-aspartate receptors and addresses the neuropathic component of tenesmus pain 6

Bacterial Dysentery (Non-Sexually Transmitted)

Clinical Recognition

• Dysenteric symptoms include fever, tenesmus, blood and/or pus in stool, occurring with Shigella, Salmonella, and Campylobacter infections 2
• Tenesmus is prominently featured in Salmonella infections (55-96% of cases) 2

Treatment Approach

• For ill immunocompetent patients with fever, abdominal pain, bloody diarrhea, and bacillary dysentery (frequent scant bloody stools, fever, abdominal cramps, tenesmus) presumptively due to Shigella: Empiric treatment with fluoroquinolone or azithromycin is indicated 2
• Empiric treatment should be considered in immunocompromised patients with severe illness and bloody diarrhea 2
• Avoid antimicrobial therapy for STEC O157 and other STEC producing Shiga toxin 2, as this may worsen outcomes 2

Common Pitfalls and Caveats

• Do not delay empiric antibiotic therapy in infectious proctitis when polymorphonuclear leukocytes are present on Gram stain, as this indicates acute inflammation requiring immediate treatment 1
• Do not use standard 7-day doxycycline regimen when bloody discharge or ulcers suggest LGV; extend to 3 weeks 1
• Do not overlook HIV testing in all patients with proctitis, as this affects disease severity and treatment approach 1
• Do not assume all tenesmus is infectious; persistent symptoms beyond 14 days warrant consideration of inflammatory bowel disease, irritable bowel syndrome, or malignancy 2
• Do not use single-modality opioid therapy for malignancy-related tenesmus; early addition of tricyclic antidepressants or antiarrhythmic drugs improves outcomes 3, 4