Hi and welcome to HCM. Thank you for your query.
It can be caused enterocolitis,allergies or congenital digestive disorders or anomalies. Also, since stool is pale you should check her liver
results to see is there any hyperbilirubinemia. For treatment you just need to prevent dehydratation and weight losing. If this persists for more than 7 days you need to do extensive work up.
Wish you good health. Regards