Ok, I got Reggie in the middle of February.  He seems to have a finicky tummy.  So far we have been to emergency vet Sunday morning twice, up all night with him last week, and now he's not eating again and his tummy is growly.  Yesterday he threw up some foamy yellow bile, but then later he was very hungry and ate dinner a while after I gave him some Pepto Bismol.  This morning he wouldn't eat (including his treat which he LOVES) but he's not throwing up.  His tummy is very growly.  He is a very picky eater so I've tried different foods with him to entice him to eat.  Even though I've changed his food a couple of times, his upset stomach doesn't coincide with the change of diet so I don't think that's the problem.
 
Anyone have any suggestions of what I can do or what I should feed him to make sure he eats consistently?