Eating issues 3 months post transplant. Still have feeding tube

My husband gags when he puts solid food into his month 3 months post heart transplant. He continues to be nauseas and has constant diarrhea over night when his feeding tube is running. Not during the day when it is not running. It’s a viscous circle that is delaying rehab (he’s been at an inpatient rehab for 5 weeks). Doctors think it’s most likely his meds and they’re looking at changing them a bit if possible. The taste and texture of food makes him gag. There may be a psychological component that is effecting his GI. I’m told it’s not uncommon after heart transplant. They’re giving him Atavan that might be holding the nausea at bay. Doctors are also saying it may be a matter of time and be patient. Has anyone experienced similar gagging etc. when trying to eat a tiny bit of solid food? How did it resolve? How long before you started to be able to accept food and get off of a feeding tube. All thoughts and comments encouraged. Thank you!