Daymond John -- Derriere Force One ... Search for the Elusive Oval Office Toilet (TMZ TV)

"Shark Tank" star Daymond John was just named Presidential Ambassador for Global Entrepreneurship -- a big fancy title that basically means ... he gets to score some face time with the prez.

And that means we might finally find out if there's a secret toilet in the Oval Office toilet! Here comes the straight poop.