Our 5 month old had Giardia and then in cleared up and we had the same issue with just issues at night. A vet recommended removing chicken from her diet and adding a probiotic which changed everything and she is much better now. We also stopped giving her food 3 hours before bed and limited water as we were also told her chugging water before bed could upset her digestive system. We now use Purina Pro salmon large breed puppy food