Hello.My Daughter Is 12.She Is Experiancing Itchiness Down There For

Hello.My daughter is 12.She is experiancing itchiness down there for a week and a hald.We went to the doctors and see if she has an infection thwy said she doesnt.She was only constipated,they gave jer !edicine for that but the itchiness did not go away.she is starting school tomorrow and i dont want her to feel uncomfortable. She has no discharge.But the itchiness is bad that she cannot sleep during the night.Please give us some help and thank you.