Hi J.,
Sounds to me like your little guy is having a hard time with the certain type of formula. I have two very sensitive little boys, 1 is now 3 & the other 11 mo. Both had extremely sensitive tummys. I breast fed & still do with the 11 mo old, holding out for 12 mo (only 2 more weeks!) I had to completely alter my diet. No dairy for me (main ingredient in formula) & with my first I couldn't even drink Soy as an alternative to milk (also a main ingredient in formula without dairy)If I had needed to give the boys formula they would have had to be on Nutramagin (liquid Gold some call it) to help them not be so gassy.
I know that babies go through many growth spurts. Especially at your guys age. Mine wanted to eat all the time. Every hour! My friend & I had babies at the same time but she was bottle feeding. She too said he was hungry every 1&1/2 to 2 hours.
Some things it could be:
Not burping after eating. Suggest keeping him upright for about 10 - 15 minutes or so after he has eaten & fallen asleep.
Milk sensitivity. Suggest switching to soy based formula
Just really hungry due to growth spurt.
Signs to watch for to tell you that it's gas:
draws up legs when crying & cries are different than say, when he wants to eat or when he gets upset during diaper change. Sometimes it's hard to tell at first, but you'll get better.
I highly recommend buying one of those big exercise balls. They are so great for babies who cry more than you'd care to hear. I wish I would have had one with my first. I was seriously bouncing on it with the baby all the time. He LOVED it & now I give it to every new mom for their shower. 3 so far & all of them tell me they use it more than the furniture! What a live & sanity saver! Get one & if he doesn't like it you can take it back. But I bet he will.
Hope not all of this is redundant stuff you already received, if not I hope some of it will help you. Hang in there, it does get better. I promise!
L.