We always try to relate everything with hcv because we do tend to become obsessed with the concept that everything is it's fault. If it's a drastic type stomach ache I'd assume it's a bug or virus (other than hcv) - although it's kind of hard for you to "get" a virus on treatment because you are on so many antivirals if you know what I mean. It could also be some improperly cooked food or something type bug.
If it's a general stomach upset nauseau type thing that isn't very violent I'd assume it's the riba. All the common stomach remedies are good (gingerale, crackers, eating smaller meals with more careful eye to what you are eating)...
Of course always have him take the riba with food (with fat!!!) as well.
It's hard for us to say what it really is since we don't know the specifics (and don't need to ;) but you should be able to tell in a few days which is was.
DO NOT TAKE TUMS OR MAALOX OR ANYTHING LIKE THAT and if he has to MAKE SURE IT IS HOURS AFTER TAKING THE RIBA OR IT WILL FLUSH IT OUT!
Nexium works good for me.
There are prescribed medications that can handle nausea. My doctor gave me Tigan which sort of helps. I know there are other things available.
I've taken Ginger Root capsules and they helped a lot too, but they also seemed to do a bit of burning to my intestinal tract. Ginger ale might help.
Papaya enzymes are good for heartburn.
Eating a very bland diet and chicken soup always helps. Small meals every few hours.
make sure he takes his riba with FOOD, a good amount of food. eat yogurt, avoid sour foods, eat fiber, maybe find diary replacements.
good luck