Daughter experiencing umbilical abdominal pain

Dear Ask The Doctor: I am a concern mother of a 17 year old senior daughter she has been having abdominal pain like a sharp knife around her belly button. i took her to the obgyn they said was stress. a gave her Maalox and the pain stays .i took her to the pediatrician , did a urine and blood test all came negative except vitamin d level was 13. i was told to give her vitamin d. i am worried because the pain is getting worse and on and off. i am schedule for a abdominal ultra sound Monday. can you tell me what it might be so we can deal with the issue and spare my child all this pain. ps pediatrician put her on 4 weeks previcid and the pain still remains. thank you sincerely shanta

Dear Shanta: It is difficult to tell what could be causing your daughter's abdominal pain on history alone. Possible causes of sharp pain in the umbilical area could be due to acute appendicitis, gastroenteritis, urinary tract infection or bacterial or fungal infection of the belly button. An ultrasound and a urinalysis will definitely be helpful in determining the cause.