Blood in Stool

Blood in the stool (poop) may be caused by irritation when moving the bowels. It can also be caused by straining very hard, by an ulcer or a tumor in the bowel, by hemorrhoids (enlarged blood vessels in or around the anus), or by a low platelet count.

What to look for

  • Blood on toilet tissue
  • Blood on underwear, sheets, or underpads
  • Streaks of blood in stool
  • Bright red blood from rectum
  • Dark red or black bowel movements (But remember that eating beets can cause red stools, and iron tablets or bismuth medicines such as Pepto-Bismol® and Kaopectate® can cause black stools for 2 to 3 days. This is normal.)

What the patient can do

  • Check how much blood is being passed.
  • Don’t put anything in your rectum, including suppositories, enemas, thermometers, etc.
  • Keep stool soft by taking in plenty of fluids and fiber.
  • Use stool softeners if OK with your cancer team.
  • Wash anal area very carefully with warm, soapy water, rinse well, and pat dry.
  • Take a sitz bath (sitting in warm water), which may be helpful for hemorrhoids.

What caregivers can do

  • Help the patient watch for bleeding.
  • Offer extra fluids, fruits, and vegetables to keep the patient’s stool soft.

Call the cancer team if the patient:

  • Has blood on toilet tissue 2 or more times
  • Has blood streaks in stool
  • Has bright red blood coming from rectum
  • Has dark red or black stools

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

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Last Medical Review: June 8, 2015 Last Revised: June 8, 2015

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