My husband has been having an internal throbbing lower left side back pain and isn t sure what the cause of it is. We went to the doctor and they said he looks normal and that it could be just muscle spasm and that he is low on red blood cells due to a complete diet change he did because he wasn t sure what was wrong with his body. We thought it was muscle spasm but realize that the pain is still there and hasn t gone away. Now he has an irritation to the area. He does not have a kidney issue. We aren t sure if he is probably allergic to certain foods. If you can provide an answer, I d appreciate it. Thank you