Let the dog eat some grass. It will help settle it's stomach. Make sure the grass hasn't been chemically treated. Grass is good for their digestive systems and will pass through. It is kind of nature's natural healer.
Pepto Bismall is what we here in the US call the "Pink Stuff". Don't know the English equivalant. However, it is an anti-dihrea,nusea,heartburn, etc... over the counter medication. Just a teaspoon or two will do the trick. Good luck!!!