Disclaimer : no intentions of self harm or anyone else : if i swallowed a bottle cap would it pass into my stool or get stuck in the esophagus?

Depends on the object's size, shape, and luck. Little pieces of stuff that are accidentally swallowed (including little bones, seeds, plastic, glass, metal...) will usually be pooped out without causing problems. Dangerous objects are magnets, button batteries, and larger or sharper intentionally-eaten items (such as in psychiatric patients). If worried, one can talk with his primary care doctor.