What probiotic with drug status can be given to a child with suspected irritable bowel syndrome?

Good morning, I wanted to ask about a good probiotic for the restoration of bacterial flora in my 6-year-old daughter, very often she has constipation or diarrheal episodes, the doctor suspects irritable bowel, we are waiting for tests and in the meantime recommended the use of an easily digestible diet and a probitic who will be the best? There is a lot of it on the market, but I want the preparation to be a medicine and not a dietary supplement. Best regards.