IBS-D could be celiac disease, which is when your body doesn't tolerate gluten (a protein found in wheat, barley, oats and rye and a ton of normal American foods). www.celiac.com
is a good site. It's estimated that about 30% of IBS-D people are actually dealing with celiac disease.Or, it could be food sensitivities - very common as well. (www.nowleap.com
for more info)Or it could be sorbitol or fructose or lactose intolerance (http://www.uihc.uiowa.edu/FRUCTOSE/index.htm
is a great fructose site.)Rather than 'live with' the diarrhea and pain, these should be ruled out. . .If your doc hasn't done these, either consider another doc, or educate yours.