Sona I am so sorry to read about Clover. Keeping her hydrated is very important. When I had Missy spayed 4 years ago her veterinary told us not to give her any solids for a good 48 hours after the surgery but plenty of water. She also had pain medicine. On the third day we gave her some solids & she threw them up. By the fourth day she held her solids down. The anesthesia takes a time to wear off & even humans can get sick from it. Peeing is a lot easier then having a bowel movement which can sometimes cause straining too. I am sorry you & Clover are having to go through this. I was a nervous wreck before, during, & after Missy's surgery. (((HUGS))) for you both.