Welcome to HCM.
It could be chyle(fat globules) or turbid urine.
is the best pErson to see, not because i am one, but we are the ones to do surgical procedure if required. But there is no harm in seeing a nephrologist
She needs urine analysis, culture, urine for chyle, renal function tests and IVP/CT scan
Based on the results treatment can be started. If pain is severe, obstruction can be relieved by a stent