My 8 month old had a UTI the doc now wants me to get a VCUG done to her? what do i do?

It seems like since she was born she was always fussy could never sleep and when she was sleeping she would make a painful face or cry i now ume thats when she was urinating it caused her pain? before i knew this we took her to a GI doc thinking she has acid reflux at 3 months because doctor kept telling me its colic its been a very frustrating road for my husband and i because our baby was still in pain we kept going to the doctors withe no answers i would tell the doctor she's not eating right she's in pain, well doctor wrote me off as another over protective mother to my new baby....she is now 8 months and we rushed to the emergency room with 103.4 fever doctors couldn't find anything wrong so took a urine sample through cat...found out about the UTI now doc wants a VCUG could kidney reflux be the problem this whole time for eight months? should i put my baby through this? has anybody else had the same thing happen to there baby please help...