Weiss Pediatric Care

Stools - Unusual Color

Definition

  • The stool color is strange or different
  • Normal stool colors are any shade of brown, tan, yellow or green
  • Colors that may be caused by a disease are red, black and white
  • Dark green may look like black, but dark green is a normal color

Call or Return If

  • Strange color without a cause lasts more than 24 hours
  • Suspected food is stopped and strange color lasts more than 48 hours
  • You think your child needs to be seen
  • Your child becomes worse

About This Topic

Causes

  • Almost always due to food coloring or food additives.
  • Stool color relates more to what is eaten than to any disease.
  • In children with diarrhea, the gastrointestinal (GI) passage time is very rapid. Stools often come out the same color as the fluid that went in. Examples are Kool-Aid or Jell-O.
  • The only colors we worry about are red, black (not dark green) and white.

Clues to Unusual Stool Colors

 

Red:

  • "Bloody stools": 90% of red stools are NOT caused by blood
  • Blood from lower GI tract bleeding is red
  • Medicines. Red medicines (like Amoxicillin). Sometimes, other medicines that turn red in the GI tract (such as Omnicef)
  • Foods. See list below.

Foods That Can Cause Red Stools:

  • Red Jell-O, red or grape Kool-Aid
  • Red candy, red licorice
  • Red cereals
  • Red frosting or food coloring
  • Beets
  • Cranberries or rhubarb
  • Fire Cheetos
  • Red peppers
  • Tomato juice or soup, tomato skin

Black:

  • Blood from stomach bleeding (stomach acid turns blood to a dark, tar-like color)
  • Foods. Licorice, Oreo cookies, grape juice, blueberries
  • Medicines. Iron, bismuth (Pepto-Bismol)
  • Other. Cigarette ashes, charcoal
  • Bile. Dark green stools from bile may look black under poor lighting. Smear a piece of stool on white paper. Look at it under a bright light. This often confirms that the color is really dark green.

Green:

  • Green stools are always normal, but they can be mistaken for black stools.
  • Bile. Most dark green stools are caused by bile.
  • Green stools are more common in formula fed than breastfed infants. It can be normal with both.
  • Green stools are more common with diarrhea. This is due to a fast transit time through the gut. However, formed stools can also be green.
  • Dark green stools may look black under poor lighting. Eating spinach can cause dark green stools.
  • Medicines. Iron (such as in formula)
  • Foods. See list below.

Foods That Can Cause Green Stools:

  • Green Jell-O
  • Grape-flavored Pedialyte (turns bright green)
  • Green fruit snacks
  • Spinach or other leafy vegetables

White Or Light Gray:

  • Foods. Milk-only diet
  • Medicines. Aluminum hydroxide (antacids), barium sulfate from barium enema
  • Liver disease. Babies with blocked bile ducts have stools that are light gray or pale yellow.

After Care Advice

Overview:
  • Strange colors of the stool are almost always due to food coloring.
  • The only colors that may relate to disease are red, black and white.
  • All other colors are not due to a medical problem.
  • Normal stools are not always dark brown. Sometimes, they are light brown, tan or yellow.
  • Here is some care advice that should help.
Green Stools:
  • Green color of the stools is always normal. Most often, green stools are caused by bile.
  • Green stools are more common in formula fed than breastfed infants. But, they can be normal with both.
  • Green stools are more common with diarrhea. This is due to a fast transit time through the gut. However, formed stools may also be green. This is normal and nothing to worry about.
  • If your child takes iron, be sure your child is not taking too much.
Avoid the Suspect:
  • Don't eat the suspected food.
  • Don't drink the suspected drink.
  • The strange stool color should go away within 48 hours.
Stool Sample:
  • If the strange stool color doesn't go away, bring in a sample.
  • Keep it in the refrigerator until you leave.
What to Expect:
  • Remove the cause of the unusual color from the diet.
  • Then the stool should change back to normal color.
  • This should happen within 48 hours or 2 stools later.

Author: Barton Schmitt MD, FAAP
Copyright 2000-2021 Schmitt Pediatric Guidelines LLC
Disclaimer: This health information is for educational purposes only. You the reader assume full responsibility for how you choose to use it.
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