hello where i come from in uk even when having a catheter in while in hospital they routinely check and measure urine output to make sure you are back to normal.
I DONT like going against doctors judgments but would advise you maybe get second opinion before three weeks.
it must be painful not being able to empty your bladder fully as normal and as you have had a uti already you don,t want to risk another infection and can,t pass urine as often to flush any more infections out.