Irritable Bowel Syndrome (IBS) Support Group
Irritable bowel syndrome is a common intestinal disorder that is characterized by bloating, abdominal pain, diarrhea, cramping, and constipation. Typically no abnormalities appear during standard medical testing, and so irritable bowel syndrome is identified by the symptoms. Although irritable bowel syndrome can cause serious discomfort, the intestines are not harmed.

Apart from the mustard I'm ok with all other ingredients in mayo. From another site I've had my question answered and will try mayo in the next couple of weeks. I've been keeping a food diary since April 2010 but thanks for the tip.
I'll try it when I go home for Christmas and save another expense if it doesn't work.