I clicked this thread because the title seemed really stupid.
The thread matches the title.
No one would use it, there isn't a need for it. As Pojo said, smell is a big indicator.
How about the huge bulge in the back. Running a hand over your diaper would accomplish the task. And the ozzy, mushy feeling.
Well Nova... you make a good point. Without some sort of feeling there probably isn't much of a way to tell if you've defecated or not. I'm pretty sure that typical "wetness indicators" work with fecal matter b/c there is typically some form of moisture present. However I imagine it is difficult to check the wetness indicator on the rear of one's own diaper. I shall ponder this and return with a suggestion.
^^ Or it looks kinda weird if you're feeling around your ass in public. *smirk*
Why couldn't they make an indicator that runs from back to front?