My little girl is 18 months old and has always had runny poo to watery poo, diarrhea. She was born at 31 weeks and has been sick maybe a little more than some of the kids we know but is generally healthy. Her poo has been tested many times for various bugs such as Rotovirus, however has always come back negative, however I read somewhere that a bowl obstruction can cause diarrhea. I have googled it but not come up with much and was wondering if anyone can shed some light on this... It would be much appreciated )