Can Mylanta Cherry Supreme cause bad gas?

So we’re (still) waiting on the Caracream-Z and have been administering Zegerid thus far with CVS brand (did you guys know Mylanta’s been recalled? Blew my mind) of the aluminum-free stuff. I’ve also, around the same time (2 days ago) started to give Simon pumped breast milk from the freezer (I don’t make enough and saved it all over the past week to see if a diet of 100% milk made a difference in his symptoms). But his gas is getting worse and worse. I haven’t done a TED (felt it ridiculous to do so when I only make 10 ounces a day); I’m inclined to believe it’s my milk that’s making him this way. But I just want to rule out the Mylanta; has it caused gas for any of your kids? This is super uncomfortable gas, not just a lot of it; he grunts and cries, and wiggles grimaces and it keeps him from sleeping.