My 12 month old son screams bloody murder every time he poops, hard or soft stool. I am concerned, especially since his twin brother has no problem passing stools at all. I am mainly concerned b/c he had bloody stools when they were in the NICU and was put on Elecare to start. He then switched to similac sensitive and has been fine, but now that solid foods have been introduced, he screams while passing stool whether hard or soft, and there is sometimes small amounts of blood on his poop. It is painful to watch and hear, I am concerned...