Thanks for your query.You had a kidney
stone which has been treated successfully by endoscopic procedure.You are worried about your blood urea being 34 mg and Creatinine
at 1.2 mg level. I would like to state that these levels are in a range of physiological standard levels,So do not worry about it.Since you had a kidney stone you are vulnerable to have reccurance of stone so drink more water and avoid urinary tract infection
which is predisposing to formation of stones.