Perhaps the guy doing the research into dehydration etc and that conducted the study last year can tell us.

I KNOW what I'd do and it doesn't involve stopping.
Having said that I've never once felt the urge maybe thats because I've "been" a dozen times in the last 30 minutes before a race.

When I raced in the newcommers race at the Manx in 1997 I stopped for my pitstop and was struck by how hungry I felt ! !