My best friend is a pediatric gastro and she always told me that if poop is black, red, or white/clay colored call the doctor.
If the poop looks clay colored or chalky, it can be a sign of a liver problem or a metabolic disorder. If the poop is just a lighter brown than usual, it's nothing to worry about.
Gena
DS, age 11 and always amazing
“Autistics are the ultimate square pegs, and the problem with pounding a square peg into a round hole is not that the hammering is hard work. It's that you're destroying the peg." - Paul Collins, Not Even Wrong