Both my husband and my mother have had kidney stones, my mother's were picked up in routine examinations and she had the lithotripsy, it was successful, but my husband was totally unexpected, we were away for a short break, and previous to that he had been hydrosliding, apparently they cause no pain until they move and hey presto that is what the hydrosliding did, made them move, he became instantly ill, and was in terrible pain, believe me i would not want to be on a long haul flight if that happened,he was rushed by ambulance to the hospital and they believed he had passed them naturally, i am told if they don't move he will be fine, good luck.,but i guess there is a slight element of risk involved.