I bought a small pack of Thorntons Vanilla toffee last week. I had four really small pieces, and 3 hours later had terrible cramping and had to run to the loo. I knew that the side effects could be unpleasant, that's why I just had a little bit, but I have to say that it worked pretty well in getting me "unstuck".
I enjoyed the wee treat though, but it's certainly not for every day. A tiny bit, every once and a while. And not before I have a party to go to!