My daughter is 5years old, she has mouth sore for last 6months with no fever. But it disappears and coming back with in 1-2days . it shows different places of mouth like inside of lips and other inside of mouth. something she experience pain uperside of belly button. I consulted local 3 -4 pediatrition and they had given vit A-Z and vit B complex and last one vit D syrups,,, but it is continuing, what can I do? plz tell me