Wash it using a pet odor neutralizer (such as Nature's Miracle, Nilodor, or Outright). Just make sure you don't use ammonia-based products - they resemble urine odor, and your dog might end up peeing...
I realize you have to go out, but maybe you should change the scheduled time for the poo. Her body might not be naturally needing to go at that time. But if she needs to go while you are gone, she...
You need to make sure that you walk your puppy until he poos before putting him in his kennel at night. If you already make sure that he poos before going in, then you are simply overfeeding him...
Just wash it using a pet odor neutralizer. But make sure you are not using any ammonia-based products - they are similar to the scent of urine, and it may encourage your dog to pee in that spot.