Intestinal pain is usually from stretching of the wall of the intestine. Most commonly this is gas, which is very good at stretching the “balloon.” If you aren’t producing much gas then you might have a partial obstruction. Something (most often an adhesion) narrows the gut opening, so when the intestine tries to push the contents past the narrowing some of that force stretches the intestine instead. You might get some relief from a liquid diet, which is easier to push past a narrowing. Partial obstructions usually clear up on their own.
The are plenty of other things that can cause the pain you describe, and the fevers are more often from some sort of an infection. I’m glad you have an appointment to figure this out. Good luck!