A lot of pain and blood happen to be at hospitals.
EDIT: I'm not the biggest cultist so can anyone tell me if the Fan Club has ever established what dwells at the ?bottom? of the pits? If there is a bottom that is.
It hasn't been fully defined. My personal usage of the pits had been that the cult dwells at the edges or along the sides of the pits. It's also possible they could dwell at the bottom of outer pits.
I envision the beating heart of any cult being its main pit, a constantly lowering inverted structure. The main pit is fed by tunnels and holes, which the cult uses to throw things down. Water, blood, other liquids, people, whatever things they sacrific, are throwing through holes and end up in a god awful mess at the bottom.
I imagine that, at some point, the pits become self propetuating. The swill at the bottom, through magic or science, continually eats away at the earth or stone blow, sinking the pit ever deeper.
In both scenarios I've run the cults worshipped the Cathartic Lobster directly, rather than Coddowalshagoth itself so that imagery doesn't have to be universal.