Overweight, Anemic Child With Regular Stomach Pain, Headache And Back Pain, Excessive Hunger, Vomiting And Watery Stools. Treatment?

My 5 year old is always complaining of her tummy hurting, headaches , and her back hurts. Not to mention her legs and feet . She sometimes walks on the sides of her feet because they hurt so bad. She is overwieght and she is hungry all the time, but she has a schedule just like my other kids. In last six mths she has had virus like problems for two days she throws up and watery stools . No, fever! and none of my other kids get it. We took her to statcare one of the times because she cried for two days after her tummy was still hurting. They did an xray and found she was impacked and did not know she had those other problems, she was anmieic, and dhydrated. But she still complains of the other problems on and off and I am concerned for her and her reason for her being overwieght !