<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi im a 17 female and ive been getting these serious sharp pains in my lower left abdemon right under my rib cage. It can get really bad to the point i feel light headed and need to sit down in the middle of a run. It usually occurs like 5 minutes into a run. ive never had this problem in my life when conditioning until about a month ago and its really getting in the way of my becoming better. What could this possible be? And is there anything i can do to prevent it?  <response>: Hi. Thanks for your query and an elucidated history. The most probable cause of such pains can be :-Colitis, inflammation of the part of the colon in the said area.-Left ureteric stone I would advise you the following:Ultrasonography of the abdomen, Tests of blood, urine and stool, Colonoscopy and CT scan of the abdomen if a 5-day course of antibiotic, metronidazole and probiotic fail to give you a complete relief. 