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Radiation or medicine damage to the intestines

Also called: Radiation enteritis, radiation proctitis, bowel damage from radiation or medicines

Radiation to the belly or pelvis, or some medicines like NSAIDs, can hurt the lining of the gut. This can cause loose stools, cramps, or blood in the stool. Diet changes and medicine help.

StartsDuring or months after radiation
SignsLoose stools, cramps, bleeding
HelpDiet changes, medicine

Overview

It can start during treatment or years later.

Pain pills like ibuprofen can also cause sores in the gut.

Symptoms

Common signs:

  • Loose stools after radiation

Less common

  • Cramps
  • Blood in stool

Look up a symptom: Diarrhea · Stomach pain

When to get medical care

Call 911Heavy bleeding or fainting.
Get care todaySigns of not enough fluid: dizzy, dark pee, dry mouth.
See a doctor soonSymptoms that don't go away.

Causes

Radiation, some medicines.

Does it spread or run in families?

  • It isn't contagious. You can't catch it from someone else.

Who is more likely to get it

  • Radiation to the belly or pelvis

Possible complications

Diagnosis

Your care team checks you.

Questions you may be asked

  • When you had radiation
  • What medicines you take

The exam

A belly exam.

Tests

Tests, if needed:

  • Stool tests:
  • Scope: A look inside the bowel.

Treatment

Ease the symptoms.

Self-care

  • Eat low-fiber foods during flares
  • Drink plenty of fluids
  • Eat small meals
  • Ask before taking ibuprofen or naproxen

Medicines

Medicines that may help:

MedicineHelps withGood to know
Loperamide
Loose stoolsAsk your care team first.

OwieClear doesn't give doses: follow the label or your healthcare professional. Medicine names here are examples, not a full list.

Which doctor treats this

  • Start with your primary care provider (family doctor or internist).
  • They may send you to a gastroenterologist (stomach and gut doctor).

Pregnancy and breastfeeding

  • If you're pregnant or planning to be, tell your prenatal provider about this condition.
  • Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
  • Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
  • Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

Outlook

Often gets better over time.

Getting ready for your visit

Bring a list of your symptoms and medicines.

Questions to ask

  • What can I eat?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Radiation or medicine damage to the intestines

Sources

Last updated 2026-11-12.