My 14 month old just had the greenest poopiest diaper I've ever seen. What's wrong? She is on amoxicillin.?

Antibiotics can take several days to kick in before they really start to work. Try to keep lots of fluids in her. My son also had severe diareah with amoxicillin. He ended up with a blistery diaper rash. If she is not improving by Monday then call your pediatrician office and ask the head nurse about it. Good luck.