Why do bookstores make some people urgently need the bathroom?

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.

Readers flooded the magazine with letters describing the exact same experience. The response was so overwhelming that the next issue ran a 14-page special feature titled "The Phenomenon Currently Shaking the Bookstore Industry!" and the condition was officially dubbed the Mariko Aoki phenomenon.

Nearly four decades later, scientists still can't explain it. Proposed theories include the smell of paper acting as a laxative, the association with reading on the toil