Why do bookstores make some people urgently need the bathroom?

By Bobby, CC BY 2.0, Link

In 1985, a 29-year-old Tokyo woman named Mariko Aoki wrote to a Japanese magazine called Book Magazine with an embarrassing confession: for years, walking around bookstores had inevitably made her need to rush to the bathroom. The editors published her letter thinking it was amusing. They were not prepared for what happened next.