Reglan causes breast development in men I think but it's still on the market and since you are a woman it doesn't really matter.
Phenegan is safe. It's been given to my kids even when they were little and really sick.
Dh has IBS. He's been through all the tests and he's had problems since his teens. He has some meds to make things better but he's always going to be bloated and have some issues. Our son has problems too but he isn't as bad as dad, he does have food issues though, dh doesn't. Ds is milk intolerant, it's the proteins. It has helped but not cured his issues.