 [ Symptoms ] i started having severe pain in my lower back and left side abdomen just under my bottom rib should my doctor do other tests [ Disease ] are you having now any pain anywhere do you have fever are you loosing any weight i do not see you do have something serious and no need for further tests however if the pain is affecting your daily life or bloody stool or started loosing weight do endoscopy and also consult an gastroenterologistmay be it is just irritable bowel syndrome and spastic colon that causes you the pain