I previously discussed Lactose Intolerance in some detail. Another less common, but possible cause of diarrhea is dietary fructose intolerance, or fructose malabsorption (FM). (This should not be confused with Hereditary Fructose Intolerance, a rare genetic disorder usually diagnosed in infancy which can lead to liver or kidney damage if not properly treated.)
If you like medical-type reading, here’s a great article on FM. http://www.healthsystem.virginia.edu/internet/digestive-health/nutrition/barrettarticle.pdf
The best test for FM is the Hydrogen Breath Test. Unfortunately, I found out that here in Portland, Oregon, that test can only be conducted at the Pediatric Gastroenterology Department at Oregon Heath & Science University (OHSU).
In fructose malabsorption, dietary fructose from food and drinks is not completely broken down in the small intestine, then is delivered to the large intestine (colon). In the large intestine, it interacts with the colonic bacteria… producing gas, bloating, and diarrhea.
Interestingly, everyone has a different capacity for fructose absorption, meaning some can absorb more than others. Also, it is quantity dependent. That can explain why you get sick with a particular food one day, and can tolerate it without problems on a different day.
FODMAPs is an acronym for a bunch of things you probably know little about…. Fermented Oligo-Di-Mono And Polyols.
The FODMAPs diet is the hottest new diet for IBS, and unlike many diets out there, it has medical research to back it up! I recommend Patsy Catsos’ Book, “IBS–Free at Last”, Second Edition and website for more in-depth look and diet details. http://www.ibsfree.net/ibsfree_at_last/
It’s definitely worth a try… especially if you feel like you have tried everything else.