Roadtrip

I have two dogs the girl is a year old the boy is almost 5 months and i go on long road trips a lot, but everytime i take them one or both gets sick most often the little puppy, if he eats he will vomit on the drive, it's gotten to the point where they cannot eat the morning of the trip. I hate the idea of boarding them due to his separation anxiety from us and her, and her hatred of dogs(she's fine with younger puppies she acts like she their mother), and the mistreatment I've seen at some of these facilities. After the drive their stomachs are messed up for days. His poop is completely liquid and he has to go 5-6 times a day(he normally only needs to go twice sometimes three times depending on his meals). Anyone have any ideas on how to settle there stomachs during and after the ride?