I’m so sorry about your poor Moms fight.  Have you tried a consultant.  Has the occupational or speech therapist  seen your Mom.  My mom has heart disease, she gets very fatigued.  I have to tantalize her, different flavors, bright colors, small amounts , frequently.  If you give them a big plate, it overwhelms them.  Try one thing at a time, easy to swallow,like ensure pudding.  You want the most calorie and protein per teaspoonful.  My mother I have to fight to get fluids in her.  Jello, puddings, soup, icecream.  It depends on her swallowing ability.  Did they check if she is emptying her bladder.  What a urologist does is catheterize her after she has just urinated, peed.  The bladder grows bacteria like a stagnant pool.  You want less than 100cc, about 5 ounces. left in the bladder.  There are catheters that are not latex.  Maybe MD trying to kill as much bacteria as possible before they catheterize her again.  I was a RN for 35 years.  I pray to God that they have checked her blood work to see how high her white cells are, and checked a fasting blood sugar.  Diabetics get infections easy.  hope things improved soon.