My 6 week old has been struggling with gas so we switched from Similac Sensitive to Gerber Gentle about a week and a half ago. He is also taking Zantac and we put a little oatmeal in his bottle (as instructed by his pediatrician) for reflux. He's always struggled to poop and pass gas, but since starting the Gerber Gentle he's pooping much more frequently...like 5 times a day...and his stool has turned green and is basically liquid. Not to mention the smell is horrible. Even though his stool is loose he still struggles just as much to poop. I feel like most of his awake time is spent grunting/straining/fussing because he's trying to poop. Its also causing him to wake up frequently at night. Could he still be adjusting to the new formula or is this a sign that it might not be agreeing with him?