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Ted Yanagihara: Algorithm for Managing Anorectal Pain in Cancer Patients Undergoing Pelvic Radiotherapy

Ted Yanagihara/X

Mar 31, 2025, 15:14

Ted Yanagihara: Algorithm for Managing Anorectal Pain in Cancer Patients Undergoing Pelvic Radiotherapy

Ted Yanagihara, Assistant Professor of Radiation Oncology at UNC School of Medicine, posted on X:

“Admittedly, radiation can be a real pain in the butt.

Here is my algorithm for managing anorectal pain in Anal Cancer and Rectal Cancer patients receiving Pelvic Radiotherapy.

Rule out skin irritation. Pain has multiple causes – a lot of patients have a component that is from dermatitis.

Minimize wiping → Sitz baths plus Peri bottle.
Start early with topical steroids (hydrocortisone for pruritus, mometasone if you expect brisk dermatitis).

Is skin irritation happening too early (Week 1-2 of RT)?

Treating a female patient with a vaginal dilator? make sure excess lubricant is not auto-bolusing perianal skin (I’ve seen this twice).

If patient starts having pain with no visible skin changes, consider HSV or VZV reactivation. Evaluate stool patterns.

Pain with BMs? Could be tumor, which can improve on treatment.

Constipation? Rule out obstruction (watch for small, frequent loose stools).

Diarrhea? If severe, loperamide, otherwise-first try:

Low-residue diet
Bulking agent (psyllium)

Pain can be from rectal spasms, caused by tumor or RT effects (I was seeing this more with short-course).

Rectal spasm = episodic, sharp, clenching pain (not always with BMs)

Can respond to anticholinergics (e.g., dicyclomine). You’ve managed the above, but there’s still more to do:

Radiation proctitis can flare after ~20-30 Gy (long-course) or 1-2 wks post 25 Gy (short-course).
Warm water sitz baths (2-4x/day)
Hydrocortisone suppositories or Proctofoam
Consider topical nifedipine

Post-RT pain peaks about 2 weeks, then improves. But watch for: Delayed worsening = Rule out infection, ulceration, or fistula.

Persistent pain? Consider:

Mesalamine suppositories
Proctofoam
Rarely, systemic steroids

Refer to surgeon if anoscopy/colonoscopy needed.

Oral pain management = simple but strategic. OTCs (ibuprofen, acetaminophen) are a starting point. Opioids thoughtfully: treat opioid-induced nausea and watch for constipation.

Think about causes, don’t just treat symptoms: Skin care, Diet modification, Targeted meds, Monitor late complications.

Your approach can make or break quality of life for these patients!”

Read Further: Anal Cancer: Symptoms, Causes, Stages, Diagnosis and Treatment.