Prilosec/Omeprazole wean

So my son is almost one. He has been on Prilosec and and we just started the weaning off it it process on Sunday. The doctor wants him getting it every other day for a month and then be done. He seemed fine until yesterday. He was crabby last night but also had a really bad diaper rash. Today his rash is better but he’s been a mess all afternoon crying and screaming at times. (It goes in waves) I’ve read online that sometimes it can seem like there is a regression with a wean but it is just their body adjusting to the change in their body. Has anyone ever gone through this?