Veterinary questions? Ask a Vet for Answers ASAP
I am sorry to hear that you are having problems with Sweep. If the lactulose has caused his stool to be very loose, then it would be advisable to stop this now. A change in demeanour such as being more placid or calm can suggest discomfort or illness so I would advise that you have her seen again by the vet. Two days is a long time for a cat not to eat and would suggest she is either feeling nauseous or uncomfortable. If she did not have any tests performed on monday, then your vet may suggest that she has these now. For example, blood tests can be used to rule out kidney disease, liver disease, certain infections. There is also a possibility that she may have eaten something she shouldn't have which can cause gastritis etc. For now, I would offer her something to eat such as chicken or white fish. I would also keep her indoors somewhere warm and quiet and let her rest until your vet is able to see you again.