I'd be inclined to go back to your normal PPI and wait until your doctor returns to ask whether the diarrhea is a temporary side effect or likely to persist. Seriously, you don't want to continue taking something that you're sure is creating that type of a problem. You obviously have a history of reacting badly to PPIs, so it makes sense to report it to your doc and hear what he/she has to say.
Are you on a maximum dose of Prilosec? If not, that might be a better route to take...just a thought.
Words of wisdom by Eckhart Tolle:
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”