Sounds as if your Shih Tzu is having separation anxiety problems because s/he's been the love of your life and vice versa and is getting older. Defecating means nothing to him. All he can think about is missing you. This shows that even when your with him outside, he doesn't want to do it. This is another indication of separation anxiety.
Keep on with with what your doing and praise him profusely when ever he does it outside. The laundry room will have to do for now. This seems to be an old age problem where his mind is focused on one thing -- you.
© Nancy Kitching 2002
Dog Trainer Member of CAPPT, CKC, OKC (Ottawa Kennel Club), and Bytown Obedience Club in Ottawa.
Hudson, Quebec J0P 1H0