Oops, it doesn't look like 'irritable bowel syndrome day' is a national day..

Other days

singles

Singles Day
polyamory

Polyamory Day
bow tie

Bow Tie Day
boba

Boba Day
ormille

Ormille Day
cursing

Cursing Day
lash

Lash Day
camera

Camera Day
kiss a ginger

Kiss A Ginger Day
offer

Offer Day