Mom (84) is having extreme abdominal pain with diarrhea and nausea. Tests show nothing. Any advice?

did they check for C-Diff from all the antibiotic use?

Did they do a stool culture? We found that mom had yeast in the digestive tract a few years ago (probably because of frequent use of antibiotics for UTI's)...It sounds strange but once we treated that (which was by oral nystatin - I think ) things seemed to fall into place.

Has blood work been done for vitamins? blood count? etc?

I am sorry for your mom's troubles. I have crohns and with a bad flare all of those symptoms can happen. Has she seen a GI doc? Might help. Tried anti nausea meds? How about dicyclomine? It helps stop spasms in the GI tract and causes few side effects. Maybe PCP at NH would give it a try.

She could have bad stomach bacteria - since as H Pylori. Trying a probiotic would certainly not hurt her and may help the nausea and diarrhea.

I started having some diarrhea after my hip replacement six years ago and had it on and off till Oct 2013 when it became extremely acute and i was hospitalized and recieved almost 2 weeks of IV antibiotics. the diarrhea eased a little and no cultures of stool revealed anything. i have had all kinds of blood testss x-rays, MRIs and a colonoscopy all with negatives results. I have lost over 50 lbs and am generally weak. Using metamucil help and every few days or before a big event i take Imodium to be sure there are no accidents if a rest room is not close.
my feeling is that all my good bacteria have been lost and can no longer resist the bad ones.
The UTIs your loved one had experienced and the subsequent use of antibiotics could have also caused her problems. She may also be lactose intolerent so it is work trying to eliminate lactose from her diet to see if it works. Also avoid fatty foods. i can't help with the pain as I have not had pain and only minimal nausia but certainly loss of appetite.

No appetite, but diarrhea? She must be eating something or there would be no diarrhea. Without a gallbladder if she eats the wrong stuff, she would be very uncomfortable. Check what she is eating.

UTIs can cause hallucinations. I did some quick googling and learned that diarrhea and pain can also be symptoms.

I'm wondering if the repeated UTIs are occurring in part because the previous episode just never completely resolved?

Perhaps she's also developed resistance to the antibiotics.

I'm also wondering if she shouldn't be seen by a urologist, or has she seen one?

I don't have any really insightful suggestions but hope that others with more experience will come along and share their knowledge.

I can certainly understand your frustration though and hope someone else offers help.