Poor baby. I agree it might be antibotic. We had that experience with one kind that required a "decent amount" of food taken with medicine. 1 pill out of the bottle ($25 later wasted) it didn't work so we had to change to another kind that required 3x a day instead of 1x a day dose.
We were told to skip a daily dose and try it again the next day, give tummy a rest. Might want to try that if it's a 1x a day dose.
Chicken and Rice is good thing Also water the rice was cooked in (rice in bag stuff) is good for them to drink.
Hope Hazel feels better.