Question
My baby has had diarrhea with acid since 2 months old. What’s going on? Can I prepare a stool sample in advance if I go to the hospital?
Answer
Normal breastfed babies can also have stool that is occasionally light green. If a baby’s stool is dark green, it indicates dyspepsia. When stool is acidic, the bile it contains oxidizes into green when exposed to air. Bilirubin, a pigment in bile, turns stool yellow when it stains it. After bilirubin is hydrolyzed, it turns into biliverdin, which makes the stool appear green. When the stool comes out and meets air in the diaper, bilirubin is hydrolyzed into biliverdin, causing the surface of the stool to turn green.