My 14yr old son Has urinary reflux. The put a catheter up the eye of his penis and they inject dye into it to see how far the dye refluxes up. I think that maybe what they mean.
My son did cry a little with the catheter going in but being held still destressed him the most.
My son has grade 3-4 ( 1 being mild, 5 being the worst). We are lucky that the urine never actually entered the kidney, it only goes to the outta wall, so that was great news. My son had a ultra sound 2 yrs ago and it shows he still has it, but because it doesn't enter the Kidney they don't see the point in operating and my son doesn't want an operation.
If it does enter the kidney, they will put him on antibiotics ( which he is probably already on as a precaution) and wait till he is older to see if he outgrows it, if he hasn't then they will talk about an operation to put in a working valve. Thats all it is, his valve from his bladder doesn't work so instead of it holding th urine it the bladder it refluxes back up.
All the best hun