Hai Gud Afternoon.My Baby Is 9 Months Old.She Is Having

Hai gud afternoon.My baby is 9 months old.She is having loose stools intermittently and sumtimes mucus is present in stools. We did stool culture and rotavirus was negative .But yeast cells are present.she also have diaper rashes.wat might be her problem?she is using similac powder and also I started introducing solid foods