Hi I Am Sarvani, Plz Help Me ...my Baby Has

hi i am sarvani, plz help me ...my baby has been on nan 1 since birth he never had any problms,then when she turned to 6 months i started giving nan2, now she is 8 months old suffering with loose motions doctor suggested to change isomil soya for 1week ...after 1 week i gve nan 2 again she had motions...plz suggested me can i use isomil r nan2..