Dear Dave,
My husband suffered from bouts of watery, yellow, foul-smelling diarrhea for months. There was no prescription pill that lessened it at all. The diarrhea would come on suddenly. We were seventy miles from home in Tucson, AZ, for George's appointment with a doctor. He had to go and I pulled into the parking lot of a restaurant. The restaurant was not open for customers yet, but there was a delivery man in the parking lot. I asked him if George could use the restroom and he replied that they would not let him in. At that time the yellow diarrhea ran down his legs, into his socks and shoes, and made a puddle on the ground. We went to the doctor's office and the girl told me where I could buy him a new pair of jeans, socks and underwear and let him clean up in their restroom. It was very embarrassing.
Then our family doctor referred him for a colonoscopy, which was negative. The doctor who performed the test mentioned celiac disease. That was the first inkling we had as to the cause of his diarrhea.
Numerous studies over the years show that Celiac Disease is much more prevalent than thought, and is often misdiagnosed. It is also referred to as "Celiac Sprue." It runs in families. It is disappointing to talk to medical doctors who have little knowledge of this condition. The University of Maryland has done some clinical trials suggesting you may be able to take a pill before ingesting gluten; however, this pill is not yet available.
I did a Google search and found much information about this condition. The only thing that stopped George's diarrhea was avoidance of flour: wheat, rye, oat and barley. Of course, malt flavoring comes from barley, and all of the cereals in the store contain malt flavoring, except Kellogg's Corn Pops and Puffed Rice.
George had been a chef and a baker, and giving up regular bread was difficult. He learned to make bread from rice flour, potato starch, xantham gum, etc. Bette Hagman's The Gluten-Free Gourmet is an excellent book. A Google search for Bette Hagman will reveal many more of her books.
Celiac.com gives a list of knowledgeable doctors recommended by celiacs. There are also Celiac Disease support groups in most states. They meet monthly and provide speakers, new recipes, tips on eating out, etc. Such a group helped my husband cope with this affliction.
George died in January 2005 from metastatic lung cancer, so I don't have to provide a special diet now.
Hope this helps.