Sorry, couldn't resist. I googled "snails' bottoms". With apologies to any Lewes residents reading.

From small-life.co.uk, a website for fanciers of stick insects and other smaller 'pets':

MYTH EXPLODED

MYTH: "Don't keep snails because of the risk of meningitis"

Wrong! It is safe to keep snails as pets and in school. The CLEAPSS organisation (concerned with science in schools) agrees and also dispels this myth on their website. The meningitis claim was silly research, based on the consequence of people licking snails' bottoms; this is clearly absurd because no sane person would do this.

From a blog about Pangasinan cuisine:

"When they are ready to cook, the snails' bottoms are patted down
with a heavy flat sandok (wooden spatula for serving rice) until
hey break."

Apparently the snail has both an anus and an excretory pore as shown here: Where do snails keep their bottoms?