Two years ago I undergone successfully a 'kidney stone' operation ( right side ) . Everthen I felt no pain up till now and healthly fully employed worker. My ploblem is often a time I feel the place becomes slightly hard and goes out at a time I could not even remember. I undergone frequent check-up at my doctor after the surgery. When told him about that and after scanning text examination, he says all is well and normal.Can you enlighten me about the cause. At moment I'm well & fit. Tnx. STEPHEN