Severe stomach pain. Functioning kidney?

My elder brother is suffering from severe stomach pain since 3 days the doctor advised for ultrasound. After ultrasound i came to know that there are some stones in right kidney(size 24*10 mm) and doctor asked for IVP test When IVP test result came when he consulted the doctor he said right kidney is not functioning. I am very worried right now he never smoked and never consume alcohol. since last 6 month he had problem of high BP and swelling in leg below part. I want to ask what were the causes for this kidney problem? what should be done in future ? what is the cost for removing right kidney and what will be the consequences when he will have only one functioning kidney? Please suggest how there should not be condition for removing right kidney.. Please help