Lots of gas, bloating and green stools. am taking a multi vitamin, the occasional antacid and codfish oil. could these be causing the green stools?

Likely basis either: things you are eating or malabsorption with bile in stool & rapid transit. If you are not digesting fats well; fats in the colon feed colonic bacteria resulting in gas & floating fecal material. Forget the multivitamin http://goo.gl/hTgfHM, antacid likely irrerelvant, codfish (like other oils) ? not being digested/absorbed. Both experiment & find someone worthy of you trust to help sort out issues

Possible: Stop each one (start with multi-vitamin) separately and see if your stools go back to normal. Regardless,if there aren't other symptoms,it's probably dietary.

Discolored stool: Most probably secondary to food colors, stop the suspected item and monitor, will answer your question

Yes: Codfish oil(cod liver oil) can speed up the transit of food thru the gastrointestinal tract if taken in too high a dose. Bile is green in color. As it travels thru the gut it's color is changed, eventually to brown. Greenish color can be the result of intestinal contents not remaining in the gut long enough to turn brown. Should return to normal color if codfish oil is stopped. SEE:abt.cm/144EnVu