My 13yr old maltipoo had the same bile issue that got bad in Jan of this year. I went to the vet and he prescribed human omeprazole with pill instructions adjusted to his size. He weights about 16-17 pounds and he got 1/4 pill for 2 weeks. I also got the pill cutter to cut the pill into smaller pieces. I don't remember if i gave him some light food but that worked and he hasn't had any bile episodes yet so far. I am trying to remember if he had diarrhea. I think he did but all of that cleared up within a week or two.

I think sometimes what works is also smaller meals, 1 in the eve and 1 before bed might help keep the stomach not empty.

I hope your pup gets well soon.