Talk to Pediatric Urologist on Kidney Pain

My younger brother, who was 16 years old, suddenly started having severe pain in the right kidney/renal area at around 5:00 AM. The pain was unbearable at first and increased in intensity despite drinking two glasses of water. During this episode, he experienced vomiting and difficulty urinating. As the pain continued to increase, I injected him. Voren 1.5 ml. After the injection, the pain gradually started to subside and he gradually started to improve. There was no blood in the urine. Due to the severity of the pain and the associated symptoms, including vomiting and difficulty urinating, what should I do and which doctor should I go to to determine the exact cause and prevent recurrence. Please give me some guidance. Thanks