Blood in Stool
Quick Answer
Blood in a child's stool can appear as bright red blood, dark tarry black stool, or blood-streaked mucus — and the appearance gives clues about where in the digestive tract it may be coming from.
What Does Blood in a Baby's Stool or Diaper Look Like?
- Bright red blood on or mixed into the stool, on toilet paper, or in the diaper
- Very dark, tarry, almost black stools that have an unusual smell
- Stool that appears mucousy or jelly-like with visible streaks of red
- A newborn with small amounts of blood in the stool
- A child who has been straining or had constipation followed by blood-streaked stool
- Blood that appears after a period of diarrhea or with a sick illness
Why Does Blood in My Baby's Stool or Diaper Matter?
- Bright red blood in stool most commonly comes from the lower digestive tract and has several causes, many of which are benign — including anal fissures from constipation or milk protein intolerance in babies and young children
- Dark tarry black stool may indicate bleeding higher in the digestive tract — stomach or upper intestine — which is taken more seriously
- A small amount of blood-streaked mucus in a well-appearing baby is different from large amounts of bright red blood in a very unwell child
This guide does not determine when it is safe to stay home.
When Should I Be Worried About Blood in My Baby's Diaper or Stool?
These are visual patterns that may deserve closer attention. This is for education only — not a diagnostic guide.
- Large amounts of bright red blood — more than a few streaks
- Dark tarry black stools in any child
- Blood in stool alongside abdominal pain, a hard or swollen belly, or a child who seems very unwell
- Any blood in the stool of a newborn under 30 days old
- Blood in stool that recurs or worsens over days
More than small streaks of blood in stool — especially with a swollen belly, significant pain, a very unwell child, or dark tarry black stool — is among the changes many parents bring to medical attention.
Knowledge Check
A 3-month-old has small streaks of blood mixed into otherwise normal-looking soft stools. The baby is feeding well, gaining weight, and seems content.
What is one of the most common causes of blood streaks in a breastfed infant's stool?
Medical References
PediaPulse content is designed and authored by board-certified pediatricians (FAAP). All pages are educational in nature and do not constitute medical advice, diagnosis, or treatment. Always consult your child's physician.