My 16month old is teething and tonight he had a dark green/black poo! normal or? his bum was very sore and skin slightly broken!

Poo: The green poo may be due the food he is eating or possible vitamins that contain iron.

Not related: Stool color usually due to what he's eating. If it's green going in, it's often green coming out. Black stop can indicate bleeding, so call your pediatrician to see if they want to see him. As to the teething at 16 months, it's a pain but it's transient. If he's 16 months old and has not as yet seen a pediatric dental specialist he's 4 months overdue.