Hi Suzy...I sometimes have the same type of diarrhea you do, hits fast sometimes right after I start eating and is yellow and slightly burning. Mine isn't set off by nerves necessarily, but I know when I get stressed I can feel the acid start in my stomach, so maybe excess stomach acid is causing yours? I also don't have a gall bladder and I think that has something to do with it, where does all that junk go when you don't have a gall bladder to handle it? lol I have GERD and IBS and my doctor has told me in the past that the yellow is sometimes caused by excess acid. I take magnesium/calcium, prilosec and an occasional zantec along with my vitamins, etc. I recently started Mastic Gum for the burning pain in my mid/upper back and rib area and it has helped for the most part, but I still have to be watchful of what I eat. Blah! And like you, sometimes I eat something and it's fine, other times it drives me over the edge!
I hope you get to feeling better