Here's a story i have written in response to Facestab Fred's request.
Prologue (Finding the panties)
Chapter 1: The First Pee (Obvious)
Chapter 2: Fun With Numbers (Discovering the pee and scat counters, then pooping)
Chapter 3: Cheaters Never Prosper (Increasing the pee & scat counters by cheating)
Chapter 4: Diaper Rash (Dealing with the effects of being unable to remove panties)
Chapter 5: Acceptance (Letting it all go)
Epilogue (Panties finally leave the MC and find their next victim)
Summary: Karen accidentally puts on some cursed panties and can't remove them. This forces her to wet herself, and eventually crap herself as she searches for a way to remove them.
Contents: Desperation, poop desperation, wetting, panty pooping, farting, and humiliation.