Hey all my little one is now 18 mnths and this morning I noticed her being very lethargic but just took it as her not being ready to wake up yet

. I put her outside to make #1 and #2 as I always do first thing,she went normally and came back in the house but then ran out again and pooped this time total wet(yuck). I then tried to feed her at her normal time and she didn't want to even go near it nor any water so I still didn't think anything of it and we went in the bed to lounge a little more and I noticed her shaking and she felt hot I then instantly knew my little pearla is not acting herself and must be sick..we got up again and I tried to give her a treat and still nothing her lethargic energy alarmed me so I gave her nutra-cal and some water in a syringe...5 mins later she threw that up. I took her out again and she pooped 3 times all wet and smelly and one looked like it had a little dark blood spec in it. I took her to the Emergency Vet and they ran all her blood work($225) it actually came back fine..so they put her on Amoxicillian and 1/4 tab of pepcid with a bland diet of pasta, white rice and potatos, boiled chicken...they said its a stomach bug/gastroenteritis. She still doesn't want to get up and or eat/drink anything do I force her to drink I'm a little nervous as to the extend of how long they can go without eating/drinking
(they did give her iv liquids in the emergency today)