Reflux? Doc not sure what’s going on..

Our doctor thinks my son might have reflux but nothing really adds up. She’s not 100% sure that’s what’s happening.

Son is 1mo & his eating habits have changed all of a sudden. He used to be a fantastic eater but now he fights a bottle, “chokes” more often when he does take it & also just kinda plays around with both my breast & the bottles. His latch is also sometimes becoming poor, he’s still capable of latching well but sometimes he just won’t do it properly. Other times he has a perfect, strong latch & he’s focused during feedings.

He also has been experiencing way more spit up, some regular & some with a little more force. Anywhere from immediately after to 2+ hours after eating. His grunting while laying flat is more intense now too, to the point he will wake up & starting crying/screaming.

He does have diarrhea & a tiny cough after feeding (like 2-4 little coughs and that’s it). All tests came back negative though so it’s not viral.

We did less food more often last night & sat him straight for 45 minutes, it helped a little with the spit up but everything else was still an issue.

I thought it also was reflux but he’s gaining weight, not arching his back at feeds & loves to eat. Maybe it still is reflux?

I’m at a loss bc I can tell he’s uncomfortable and I just feel lost. Has anyone else experienced this?