I'm right there with you with Bijou. I've actually got an appointment with my vet on Thursday to have her checked for any parasites that may be causing her to want to eat it. which I don't know how they'd miss it before since she's still a pup and has been wormed and checked and on heartguard meds, but you never know. But she eats my other dogs pooh right after they go if she's outside with them. It's soo weird. If she is left outside at the same time the boys go out she will bark a lot and jump at them like she's trying to get them to go if they do she will try to eat it. I've intervened once I seen this is why she was barking so wildly when they all go outside. I've had to stop letting them out together until I can get her to stop this nasty habit. I've tried giving her the pills from the pet store (it's Excel deter Coprophagia Treatment) they work, but once I stopped giving them to her after the two weeks recommended she was right back to eating her pooh again.
I've done all the changing of foods with her too. She currently on Wellness. Was on Innova puppy then Evo and it didn't work, so I thought maybe she wants cheap stuff so we tried the purina benaful (sp?) she loved it, but still ate her pooh. The scary part is that it gives her runny pooh and I've seen some blood in there so I set up the appointment with her doc and canceled her spay for now. Plus I seen the recall on the medicines so I don't want to take any chances. I'll ask the vet about them when we're there on Thursday too. I'll let you know what the vet says if you like. Just PM me as I'm sure this thread will be lost in all the new ones. I feel your pain