The most common signs and symptoms of
kidney infections are nausea, vomiting, abdominal fullness, lower back ache,
frequent urination, the urge to urinate, pus or blood in the urine, fever. A complete history, clinical examination and investigations may be helpful. Tests like endoscopy, ultrasound abdomen, kidney, ureter bladder and Barium studies may be needed for confirming the diagnosis. I hope it helps. Do keep us posted on how he is doing.Take care and regards.