my 8 week old baby is on enfamil newborn and his burps smell like rotten eggs. This started when he was on similac sensitive, wechanged formulas due to the smell and heqas sspitting up the formula and it looked chunky and he couldn t poop. Now that hes on enfamil he spits up but it looks lije water he poops alot but makes his butt red his burps smell like rotten eggs and he will cry as if something hurts him. What can I do for him?