bichon frise dog

My dog (Bichon Frize) is 4 1 / 2 years old and lately has been peeing and poo in the house!?
Usually in the middle of the night and left me out every night before bed and allow him enough time to do his thing. I do not understand why from this? Does anyone know why this might be doing this? He has before in the past, but improved and stopped for a long time, now its starting again. Any response would be helpful. Thanks!
Good, could be that he ate something different. Dogs are very complicated when it comes to food. I have a female of 6 years and she has to eat specific foods. They get skin allergies and so on. Just recheck your diet or try to remember the last thing you ate and when he ate. Feed him about 8 so you have time to release something before 10:30 hours. Hope this helps
BICHON FRISE DOG THINKS HE’S A CAT