Try using soy formula. My daughter sleeps longer and is not as fussy or irritable!!
If this doesn't help, there is a second med your son can take as well. My daughter is on two of them for reflux issues. It doesn't help the spit up...but helps the pain.
My son did the same thing. He even would arch his back trying to get relief. We took him to the ER last night because the screaming got worse and it was as if he was in excruciating pain. He would be content while eating and then as soon as he finished he'd start wailing. ER said its colic which I've learned is the term for they don't know what's wrong with your baby. So don't take it as colic and let it go because those first 6 months will be hell. Followed up with his pediatrician this morning and I'm glad we did. My son had a "colic" episode in the docs office and the doctor said it's not colic it's mild reflux where the acid from the stomach comes up the esophagus like acid reflux or heartburn in adults. He prescribed my son a medicine to neutralize the acid and take away the pain and discomfort. It's only been one dose so far so can't really tell but we'll see over the next few days. Talk to your baby's doctor.
I'm sorry. Are you sure its colic and not acid reflux? With reflux, it could be the acid causing pain. Try looking up a messy eater and try those tip, and is try having her sleep in her swing or something at a 30 degree angle and see if it helps.