Need answers have an elder 75 aunt, diagn. w/klebsiella bacteria urine, 2 rounds of macrobid not working, bowel changes since bacteria, constipated, seems as bowel meds not very helpful, behavior/personality changes. what else can be going on?

Many possibilities: From a bowel condition causing constipation, benign or malignant to a metabolic disorder, such as hypothyroidism, including poorly defined neurological disorders from the dementia spectrum anything is possible. She needs a good workup with her doc that should expand past the UTI that is not likely to be causing the problems, but rather the late effect of them.