Dark Blood in Baby's Stool
Medically reviewed by Dr. Sarah Chen, MD, FAAP · Board-Certified Pediatrician
Content reviewed against published AAP, NIH, AAP guidelines
Last reviewed:
Digestive issues are common in infants and toddlers. If your baby is experiencing dark blood in baby's stool, here is what you need to know.
The short answer
Dark or black blood in stool (melena) is different from bright red blood and may indicate bleeding from the upper digestive tract (stomach or upper intestine). In newborns, black stools in the first few days (meconium) are normal. Beyond the first week, dark, tarry, or coffee-ground-like material in stool needs prompt medical evaluation. Some dark-colored foods and iron supplements can also darken stools without being blood.
Key takeaways
- Dark or black blood in stool (melena) is different from bright red blood and may indicate bleeding from the upper digestive tract (stomach or upper intestine). In newborns, black stools in the first few days (meconium) are normal. Beyond the first week, dark, tarry, or coffee-ground-like material in stool needs prompt medical evaluation. Some dark-colored foods and iron supplements can also darken stools without being blood.
- Usually normal when: Meconium in the first 2 to 3 days of life
- Call your doctor if: Black, tarry, foul-smelling stool (melena) that is not meconium or from iron supplements
- Varies by age — see the age-by-age breakdown below
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What Parents Should Know
According to AAP, NIH guidelines, dark or black blood in stool (melena) is different from bright red blood and may indicate bleeding from the upper digestive tract (stomach or upper intestine). In newborns, black stools in the first few days (meconium) are normal. Beyond the first week, dark, tarry, or coffee-ground-like material in stool needs prompt medical evaluation. Some dark-colored foods and iron supplements can also darken stools without being blood. At 0-3 months, meconium (black, tarry stool) in the first 2 to 3 days of life is completely normal. After transitional stools, any return of black, tarry stool should be evaluated. In breastfed babies, dark blood in stool could be from swallowed blood from cracked nipples. Your pediatrician can test the stool to determine if the blood is from the baby or the mother. It is generally considered normal when meconium in the first 2 to 3 days of life. However, you should contact your pediatrician promptly if black, tarry, foul-smelling stool (melena) that is not meconium or from iron supplements.
Normal vs. Concerning
By Age
What to expect by age
0-3 months
Meconium (black, tarry stool) in the first 2 to 3 days of life is completely normal. After transitional stools, any return of black, tarry stool should be evaluated. In breastfed babies, dark blood in stool could be from swallowed blood from cracked nipples. Your pediatrician can test the stool to determine if the blood is from the baby or the mother.
3-6 months
Dark blood in stool at this age is uncommon and needs evaluation. Possible causes include Meckel diverticulum, intestinal duplication, or other GI conditions. Iron supplements can darken stool to a greenish-black color, which is harmless. If you are unsure whether the dark color is from iron or blood, save the diaper and contact your pediatrician.
6-12 months
Dark or black stools can result from iron-rich foods (like fortified cereal or meats), iron supplements, or bismuth-containing products. These causes are harmless. True melena (black, tarry, foul-smelling stool) indicates upper GI bleeding and needs prompt evaluation.
12-24 months
Dark-colored foods like blueberries, beets, and dark chocolate can darken stool. Iron supplements commonly cause dark green to black stools. If your toddler has not eaten dark foods or taken iron and has black, tarry stools, contact your pediatrician promptly for evaluation.
What to Tell Your Pediatrician
- Describe when you first noticed dark blood in baby's stool and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if dark or black stool that is not clearly explained by food or supplements.
- Mention if you are unsure whether stool darkening is from iron or blood.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
What Should You Do?
When to take action
- Meconium in the first 2 to 3 days of life
- Dark green or black stool from iron supplements or iron-fortified foods
- Dark stool after eating dark-colored foods like blueberries or beets
- Dark or black stool that is not clearly explained by food or supplements
- You are unsure whether stool darkening is from iron or blood
- Black, tarry, foul-smelling stool (melena) that is not meconium or from iron supplements
- Dark bloody stool with vomiting, abdominal pain, or pallor
- Any significant amount of blood in stool at any age
What You Can Do at Home
- Keep track of when you notice dark blood in baby's stool — noting the time of day, duration, and any triggers can help your pediatrician.
- Remember that meconium in the first 2 to 3 days of life — this is generally within the range of normal.
- At 0-3 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
- Keep your baby upright for 20-30 minutes after feeding. Note any patterns between feeds and symptoms.
- While monitoring at home, seek immediate care if black, tarry, foul-smelling stool (melena) that is not meconium or from iron supplements.
Related Conditions
Blood in Baby's Stool
Seeing blood in your baby's stool is understandably alarming, but the most common cause in young babies is a small anal fissure (a tiny tear from passing stool) or swallowed maternal blood from cracked nipples during breastfeeding. However, blood in stool always deserves medical evaluation to rule out less common but important causes like a cow's milk protein allergy or infection.
Baby Black Poop
Black poop in a newborn's first few days (meconium) is completely normal and expected. Black or very dark green stools can also be caused by iron supplements or iron-fortified formula. However, black tarry stools outside of the newborn period that are not explained by iron can indicate digested blood from higher in the digestive tract and should be evaluated by a doctor promptly.
Blood Streaks in Baby's Stool
Bright red blood streaks on the surface of stool or on the diaper are most commonly caused by a small anal fissure (tear) from passing hard stools. This is very common and usually heals on its own when constipation is treated. Other causes include cow's milk protein allergy in young infants or minor rectal irritation. While usually benign, blood in stool should always be mentioned to your pediatrician.
GI Bleeding Causes in Baby
Gastrointestinal bleeding in babies has many possible causes, most of which are benign. The most common cause of rectal bleeding is an anal fissure from constipation. Other causes include cow's milk protein allergy, infectious colitis, Meckel diverticulum, and intussusception. The color and amount of blood, along with associated symptoms, help determine the urgency and cause.
Related Resources
Poop Color & Texture Guide
What your baby's poop color and consistency mean, and when to worry.
Month-by-Month Development
Detailed monthly development guides from birth through 24 months.
When to Call the Doctor
General guide on when to call the pediatrician, visit urgent care, or go to the ER.
Frequently asked questions
Is dark blood in baby's stool normal?
When should I call the doctor about dark blood in baby's stool?
When is dark blood in baby's stool normal?
What causes dark blood in baby's stool?
What should I mention to my pediatrician about dark blood in baby's stool?
Is dark blood in baby's stool normal at 0-3 months?
Is dark blood in baby's stool normal at 3-6 months?
Should I go to the ER for dark blood in baby's stool?
Does dark blood in baby's stool go away on its own?
References
Doctor Visit Checklist
Bring this checklist to your next pediatrician visit to discuss Dark Blood in Baby's Stool.
Things to mention
- Describe when you first noticed dark blood in baby's stool and how it has changed over time.
- Note your baby's current age and which age-specific patterns you are seeing.
- Mention if dark or black stool that is not clearly explained by food or supplements.
- Mention if you are unsure whether stool darkening is from iron or blood.
- Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
- Bring a list of any questions or observations you want to discuss at the appointment.
Observations to share
- Dark or black stool that is not clearly explained by food or supplements
- You are unsure whether stool darkening is from iron or blood
Urgent signs to report immediately
- Black, tarry, foul-smelling stool (melena) that is not meconium or from iron supplements
- Dark bloody stool with vomiting, abdominal pain, or pallor
- Any significant amount of blood in stool at any age
My notes
From ismybabyalright.com — free, evidence-based baby health guides
All content follows our editorial policy and is reviewed against published clinical guidelines.
2,705 evidence-based guides6 authoritative medical sources5 medical advisory board members
Related Resources
Bottom line
Most cases of dark blood in baby's stool are normal. Talk to your pediatrician if black, tarry, foul-smelling stool (melena) that is not meconium or from iron supplements.
Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.
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Related Digestive Concerns
Blood in Baby's Stool
Seeing blood in your baby's stool is understandably alarming, but the most common cause in young babies is a small anal fissure (a tiny tear from passing stool) or swallowed maternal blood from cracked nipples during breastfeeding. However, blood in stool always deserves medical evaluation to rule out less common but important causes like a cow's milk protein allergy or infection.
Baby Black Poop
Black poop in a newborn's first few days (meconium) is completely normal and expected. Black or very dark green stools can also be caused by iron supplements or iron-fortified formula. However, black tarry stools outside of the newborn period that are not explained by iron can indicate digested blood from higher in the digestive tract and should be evaluated by a doctor promptly.
Blood Streaks in Baby's Stool
Bright red blood streaks on the surface of stool or on the diaper are most commonly caused by a small anal fissure (tear) from passing hard stools. This is very common and usually heals on its own when constipation is treated. Other causes include cow's milk protein allergy in young infants or minor rectal irritation. While usually benign, blood in stool should always be mentioned to your pediatrician.
GI Bleeding Causes in Baby
Gastrointestinal bleeding in babies has many possible causes, most of which are benign. The most common cause of rectal bleeding is an anal fissure from constipation. Other causes include cow's milk protein allergy, infectious colitis, Meckel diverticulum, and intussusception. The color and amount of blood, along with associated symptoms, help determine the urgency and cause.
My Baby's Belly Looks Swollen
A rounded, slightly protruding belly is completely normal in babies and toddlers due to immature abdominal muscles and their proportionally larger organs. However, if the belly becomes suddenly swollen, feels hard and tight, or is accompanied by pain, vomiting, or changes in bowel movements, it needs medical evaluation as it could signal gas buildup, constipation, or rarely, something more serious.
My Baby Has an Anal Fissure (Blood When Pooping)
A small streak of bright red blood on the surface of your baby's stool or on the diaper is most commonly caused by an anal fissure, which is a tiny tear in the skin around the anus from passing hard stool. Anal fissures are very common in babies and toddlers and usually heal on their own with simple measures like keeping stools soft. While this is rarely serious, any blood in your baby's stool should be mentioned to your pediatrician.