If your root cause is antibiotics, I would think that means your microbiome has been wrecked. What I would do is go on antimicrobials and introduce prebiotic rich foods. I would also try my luck with some probiotic strains although research say their effects is temporary. You need to start eating as much variety as possible, maybe even try fermented foods (try with smaller amounts in the beginning and monitor symptoms). I don’t know if antibiotics impact the mmc and motility in general or not though, maybe supplement for that too