What Causes Different Colored Stool ?

Patient Presentation
A 2.5-year-old boy is brought to the clinic because of flecks of blood in his stool. He had two stools this morning that had red colored specks mixed throughout the stool. There were previously normal bowel movements and there has been no mucous in the stool. He has no recent painful or large bowel movements and he has been playing, eating and acting normally. His family history and review of systems are negative. On physicial examination his abdomen is soft and non-tender with no organomegaly and normal bowel sounds. His anus shows normal tissue without fissures. His genitourinary examination is normal. The laboratory evaluation showed the stool to have 1-2 mm bright red speaks throughout the formed stool. Hemoccult was negative. With further questioning, the mother remembers the boy coloring yesterday. During clean-up she wasn’t able to find all the crayons including a red one. A clinical diagnosis of red crayon ingestion was made. The mother is told that the flecks will clear with additional bowel movements. She is instructed to monitor the boy and call if any problems arise.

Most stool color changes are harmless. They often are due to eating particular food or drugs. The changes can also be caused by dyes in foods such as brightly colored breakfast cereal or children’s art supples such as non-toxic crayons, markers, and paint. Usually parents can be reassurred that that once the child stops ingesting the offending agent, the stool will return to normal in a short time. A patient or caregiver factitious disorder can also present with different colored stools because of ingested agents or colorings added to the stool.

Sometimes infections or other medical problems cause changes. It is important to exclude potential problems such as upper or lower gastrointestinal bleeding as the cause of a red stool. Rectal fissures caused by hard stools are a common cause of “bloody stools.” Blood from a rectal fissure is usually streaked on the stool, diaper or underpants and not mixed in the stool.

Learning Point
The causes of stool color changes are listed below by body/cell contents, diseases, drugs, foods, infections and other causes.

  • Red/Pink Stool
    • Blood
    • Diazepam syrup
    • Ampicillin
    • Viprynium
    • Phenophthalein
    • Red Jell-O
    • Dioralyteoral rehydration solution
  • Yellow Stool
    • Normal in formula-fed babies
  • Green/Greenish Gold Stool
    • Normally in fully breastfed babies
    • Stomach infection
  • Black Stool
    • Blood
    • Iron
    • Pepto-Bismol
    • Black licorice
    • Blueberries
    • Green-leafy vegetables
    • Lead
    • Charcoal
    • Coal
    • Dirt
  • White/Clay Colored Stools
    • Malabsorption
    • Biliary system blockage
    • Barium
    • Aluminum Hydroxide

Questions for Further Discussion
1. What are common causes of bright red blood by rectum?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at Pediatric Common Questions, Quick Answers for this topic: Stool and Urine Color Changes.

Sheldon SH Levy HB. Pediatric
Differential Diagnosis, Second Edition. Raven Press: New
York. 1985. pp. 22, 156.

Schiff D, Shelov SP. American
Academy of Pediatrics. The Official, Complete Home Reference:
Guide to Your Child’s Symptoms. Villard: New York. 1997. pp. 587.

Illingworth RS. Common Symptoms of Disease in
Children. Blackwell Scientific Publications: Oxford. 1998. pp. 95, 97.

Gunn VL, Nechyba C. The
Harriet Lane Handbook. 16th. Mosby Publications: St. Louis. 2002. pp. 387-98.

Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa

November 15, 2004