Well cranberry is the stuff we eat at Xmas or Thanksgiving depending on where you come from, and Viburnums are ornamental shrubs we have in the garden which we grow for their pretty flowers/perfume/berries.

The plant we are talking about is usually known as the Snowball bush or Guelder rose, personally I've never heard anyone call it a cranberry, but it's one of many names listed for the plant on Wikipedia. I just know it by its Latin name. It does save a lot of confusion.
But I am not nitpicking with you but just highlighting the fact that it wasn't cranberry as we think of cranberry in case anyone reading this doesn't know their shrubs and went off thinking they'd make their cranberry sauce for crimbo or a drink from a Viburnum! We have to have some warnings on here as anyone can read this.
However I wouldn't be surprised if eating tons of real cranberries gave your diarrheoa or stomach problems, after all we wouldn't eat tons of elderberries or anything else sour would we? And even eating plums can give some people the trots.
