II. Exam: Normal Stool
- First few newborn stools are normally black and tarry (meconium)
- Subsequent stools become yellow-brown with a seedy consistency
- Normal stools may also vary from green to a darker brown
- Stool frequency varies between several times daily to every few days
III. Causes: Dark or black stool or bloody Emesis (upper gastrointestinal source)
- Upper Gastrointestinal Bleeding (uncommon in newborns)
- Ingested blood from cracked maternal nipples during Lactation
- Swallowed maternal blood from delivery
- Distinguish newborn blood from maternal blood with the Modified Apt Test
- Fetal Hemoglobin contains 2 alpha subunits and 2 gamma subunits (contrast with beta subunits in adults)
- Fetal blood is resistant to denaturation when alkali is applied (fetal blood remains pink)
- Adult blood denatures in contact with alkali and turns brown
IV. Causes: Bright red stool (lower gastrointestinal source)
- Precautions
- Exclude serious causes before assuming a benign cause of neonatal Lower GI Bleeding
- Ill appearing infants should undergo extensive work-up
- Larger volume bleeding (even in well appearing infant) may warrant observation in hospital
- Serious Causes (typically with an ill appearing infant or complicated history)
- Necrotizing Enterocolitis
- Intestinal mucosa ischemic necrosis complicated by gut Bacteria translocation across the intestinal wall
- Consider especially in Premature Infants, or those with complicated birth history
- Among the first diagnoses to evaluate in an Ill appearing newborn
- Obtain Abdominal XRay
- Malrotation with Midgut Volvulus
- Intestinal Obstruction with progressive Vomiting
- Evaluate with upper GI study
- Intussusception
- May present even in newborns with intermittent inconsolability
- Hirschprung-Related Enterocolitis
- History of Hirschprung's Disease is often already diagnosed or history of not passing meconium on day 1
- High risk of perforation (avoid Rectal Exam, rectal medication, enemas)
- Consult pediatric surgery emergently
- Vitamin K Deficiency
- Consider in infants that did not receive Vitamin K at birth (e.g. out of hospital delivery)
- Coagulopathy (e.g. Sepsis, liver failure, Coagulation Factor deficiency)
- Rarely presents as Gastrointestinal Bleeding (other bleeding sites are more common)
- Obtain Complete Blood Count
- Necrotizing Enterocolitis
- Benign Causes (well appearing infant)
- See Swallowed Maternal Blood (Breast fed infant) as above
- Milk Protein Allergy
- Anal Fissures
- Uncommon; consider Constipation Causes including Cystic Fibrosis
- Avoid diagnosing an Anal Fissure without actually seeing the fissure
- Food or medication ingestion
- Red Gatorade
- Baby Percy (Pepto-Bismol like product containing Salicylates, which infants should NOT be given)
V. Causes: White Stool (acholic stool)
- Biliary Atresia
- Requires emergent evaluation and Consultation (best outcomes are with early management)
- Other biliary tract lesions
- Biliary tract cyst, bile plugs or stones
- Biliary tract tumors
- Neonatal sclerosing Cholangitis
VI. References
- Mason and Woods in Herbert (2019) EM:Rap 19(2): 7-8