My 17 Year Old Daughter Was Experiencing Sharp Pains To

My 17 year old daughter was experiencing sharp pains to her left lower abdomen. Dr. did an xray and we were told she had air pockets due to lack of water intake and suggested a liquid diet for a few days. Although, she drinks plenty of water In her diet, pain finally went away. One month later, pain is back. Any suggestions why symptoms occur and what she can do to prevent them from coming back? Could this also lead to something more serious?