We had some similar reactions to prevacid. We were on prevacid for 2 months. It made a huge improvement in the reflux pain area, but like clockwork about an hour or so after each prevacid dose, DS was super gassy, squirmy, fussy. We just switched to zegerid(tums buffer) last week and DS has been a totally different baby. I thought he was doing well on prevacid, but since being on zegerid there has been even more improvement and no more fussy, squirmy gassy episodes. He is a pretty happy baby these days. Our GI told us that the lactose in the prevacid might be an issue if LO was lactose intolerant, but should not be a problem with MSPI.(then went into the whole its very very rare for babies to have a true lactose intolerance, etc) I asked her to humor me and switch his meds. I am so glad we did. So, who knows what caused the episodes, but the important thing is after switching to zegerid they resolved.