Comes from “this report”:http://www.guardian.co.uk/life/thisweek/story/0,12977,984688,00.html in today’s Guardian — Every half-hour for six hours afterwards, the researchers emptied the volunteers’ colostomy bags and tested the contents for a specific gene that had been spliced into the GM soya.
I found it browsing for a “piece of mine”:http://www.guardian.co.uk/life/interview/story/0,12982,984721,00.html on Larry Trask.