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 in the first month of life
- Obtain Abdominal XRay
 
- Malrotation with Midgut Volvulus- Intestinal Obstruction with progressive Vomiting in first month of life (60-80%) and first year of life (90%)
- Evaluate with upper GI study
 
- Intussusception- May present even in newborns with intermittent inconsolability
- Most commonly presents age 3 months to 2 years old
 
- 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
 
- Meckel Diverticulum- Painless intermittent bleeding is the most common presenting symptom in children
- Although average age of presentation is 5 years, may occur at any time including neonatal period
 
 
- 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
