Do they always culture your urine before they treat UTI.? Some bacteria is not sensitive to the same Antibiotics as the most common E.Coli is. Always insist on a culture. Some E. Coli is resistant to the standard antibiotics. With the diarrhea, it in itself can splash up and make its way into the bladder via the urethra. Especially if you are a older woman. I would definitely talk to your Doctor about going on the probiotic Florestor for your bowel problems. It is a reputable brand and quite often recommended by doctors. It is expensive but I think we'll worth the try. It is great to take while on antibiotics because they can't kill it like Standard probiotics. Some studies have shown a possibility that it might even ward off c.dificil infections.
I know what you are going through. Iam a 76 year old woman and have had diarrhea on and off since I was in my 20,s...diagnosed as IBS (Irritable bowel syndrome). Since a prolapaed uterus followed by a hysterectomy I also get UTI,s easily. I always practice all the preventative measures when bathing and going to the bathroom. This last UTI was a bd one and when the first treatment did nothing it was because it was caused by Enterococcus faecalis (E. Faecalis) not E. Coli. It is a very resistant bacteria. There are only a few antibiotics that treat it. So please insist on a urine culture. I also know how all this can cause emotional turmoil like Anxiety and Depression. Hang in there...you got this.