I am aiding my sister in trying to figure out what is wrong with her cat. Of course the vet is treating her, but he is puzzled as well. 4 days ago the 6 year old cat developed lethargy and vomiting. She went to the vet on Thursday and blood tests were run - a geriatric panel which consists of a CBC, Renal and Kidney function and a few other tests which my sister does not know the names (the blood tests were normal). He also took and x-ray of the cats abdomen which did not reveal any obvious abnormalities. The cat was given a shot of steroids and a med for nausea. She was also given sub-q fluids as she was dehydrated. Friday she went back to the vet and was given more sub-q fluids which perked her up and she seemed almost normal but by Saturday afternoon she was developing the lethargy again and will not eat or drink so the fluids were given again and he taught my sister to administer them. He has not come up with a diagnosis yet but suspects it might be irritable bowel syndrome. It came on suddenly and after several days she still is not drinking. She took a few very tiny bites of food but is still not eating anything tonight . My sister is so upset as this cat is her baby and I am just trying to see if anyone has any ideas from past experiences that may help figure out what is going on. The vet said that the only step now to take is exploratory surgery if the cat does not show any improvement by Monday.
Thanks to all who ake the time to respond!

Firstly my heart goes out to your sister, I have a 17 year old cat and over those years I have nursed her on several occasions, as any cat owner will tell you, the cat is one of the family. I have a pdf ebook (a brilliant book, used it time and time again); Cat Owner's Home Veterinary Handbook, due to the rules of this site I cannot post the Link to the book (as its considered illegal).

Go into your Control Panel, Edit Options, and Enable Private Messaging and Save Changes, I will check back again and send you a private message with the download Link. I may get into trouble here for doing this, may even be banned from this site, but I'll take that chance as where a cat's health is concerned, I'd do anything to help one.