100, 000 E.coli colony in urine. Having back pain, flank. No fever. How can I differentiate btwn pain from urinary infection or pain from kidney stone?

SEVERITY. LOCATION ...Kidney STONE pain is VERY SEVERE (9-10 out of 10) and MOVES as the stone moves.
Infection per se is usually not painful...and is accompanied by OTHER symptoms eg: BURNING on urination!
Hope this is helpful!
Dr Z.
Usually. Pain from bladder infection/UTI are usually describe as pain on urination like burning. Flank pain can be associated with Kidney stone or Pyelonephritis.