Hi Welcome to HCm I have gone thru your query regarding lower back pain of your son . It is matter of concern . The majority of back problems stem from muscles that have been exhausted or strained. You need not worry , Almost every one suffers from back pain at some point in his or her life. Your son does not seem , having symptoms of kidney related problm . By following some simple steps, you can be back in the swing of things in just a few days. Take balanced diet containing all essential nutrients and supplements like fiber ,protien , vitamins , minerals in natural form and antioxidant coco nut water , lemon juice , ginger ,garlic aloe vera juice ,Turmeric powder with a cup of hot milk at bed time , All help gain strong immune system & give resistance from dieases and relieve you from all pains . Increase your activity level .Do yoga .Stretch your back to keep it loose and avoid injury. Avoid front bending stretches and exercises from left to right stretching , while standing & lying on your back ,on the ground or on hard bed , or any posture which gives you relief. Front bending not allowed. Take Homeo pathic Arnica 30 dose in then morning & evening and Chammomila 30 / 1 dose at bed time. Only back bending action will help alley pains . massage with heated olive oil or an analgesic ointment and Keep good posture . I would like to suggest you to Avoid processed foods carbs , sugar , fried ,fast foods , Tea , coffee , alcohol and smoking , stress and Constipation . All produce biochemical and metabolic conditions in your body that will decrease your immunity, so avoiding is definitely the first step in the right direction to detoxing the body, boosting the immune system . meditation also gives peace relieve pains A key factor is determining whether your lower back pain is accompanied by other symptoms of kidney infection, including fevers and high temperatures, an upset stomach, cloudy, bloody or malodorous urine, and more frequent urination . Best way is to Always remember, if pain is severe or incapacitating, please see your doctor / professionaland ascertain the actual cause of the problem . Hope this helps solves your query .Take care .All the best .Get well soon Don t hesitate to come back in case of any further query .