About your UTI yes it can cuase wide spread pain in the abdomen, a UTI is and infection of the unrinary tract which could be you kidneys (left and right of your back below the rib cage). Ureters (tubes of your kidneys that carry urine to the bladder), Urinary bladder (stores urine) and the Urethra (pathway that releases urine out side the body) all of these are locate from the mid back to the pubic region and it is normal to have pain spread through out. The Fatigue is most likely caused by the kidneys are not fully functioning because of the infection, and also becuase of the infection your body is fighting off. Now about the sulfa antibiotics, i assume you are on Bactrim, there are cases of Bacterial resistance, so call your doctor and tell him that the pain is still there and it is not getting better and he may prescribe you a Quinolone (Ciprofloxacin). Hope this helps.
I have pain in the right side, flank and back. I have a history of kidney stones, but a ureteroscopy/cystoscopy showed normal kidneys. I've had ultrasounds as well. I do not have an appendix, or gallbladder. I do have Crohn's disease, but it has never caused me to have back pain. My GI says it's the urinary tract, my urologist says it's my GI. I also recently have been diagnosed with high triglycerides, and type 2 diabetes. Any ideas on what is causing my severe pain. I could have sworn it was a kidney stone, but that was negative. I also have been running a fever of around 100 degrees.