"Now, he had a fever, bilirubin in his urine, and his stomach has fluid
in it. What does all of this mean? Is it getting close to the end for
him? "
I wish I had a very similar experience.... However, I can tell you this, my father went for a short period where he was having a problem with lots of bilirubin in his urine as well. It was not a huge deal. It was something that passed just fine. Fluid in his stomach organ? This seems like a symptom that would be easy to fix--a nasogastric tube perhaps? I don't know. Is the tumor preventing his stomach from emptying? My father had fluid collect in his abdomen. The doctors did a needle aspiration to drain the fluid and bring him comfort.
I don't think these are necessarily signs that it is the end for your loved one. However, they are things that should be addressed and fixed by your physician immediately. They are complications--but what that means for how extensive the cancer is I wouldn't know.
It sounds like you have a lot of questions that you need to get answered by you doctor. You should make a list, and then go in, or call him/her. Make sure you get all of your questions answered, and that you understand the answers. My family finds it helpful to have several family members there each time, because we all pick up different pieces of information from the doctor--we all remember different things. Don't be afraid to ask up front, "Is this the end for us? How much time do we have?" But also make sure you always ask "What can we do to try to fix this?" You need to walk away with something that will empower you.
Best of luck.