And I really think the fish oil had a lot to do with healing up my gut symptoms, although I guess B12 deficiency does cause GI symptoms, too. It is hard to know what helped me most...because I was doing several things at once.
Gastrointestinal symptoms include heartburn, flatulence, constipation, diarrhea, sore tongue, and early satiety.
http://www.emedicine.com/neuro/topic439.htm