Roach: ‘Low FODMAP’ diet is effective for digestion-related ailments
DEAR DR. ROACH: In a recent column, you described symptoms of malabsorption as weight loss, diarrhea and abdominal discomfort. My doctors have never mentioned this as a possible diagnosis. Is there anything to do for it other than avoiding high FODMAP foods (which I have been trying to do)? At times, I fear that I am not getting proper nutrients eating the way I must. — L.B.
ANSWER: Malabsorption is when your body cannot take in the nutrients you need from the food you eat. It always needs a thorough investigation in order to make a precise diagnosis, since treatment depends on the underlying cause.
The most common cause in North America now is probably celiac disease, which is a sensitivity to a protein found in wheat and other grains. Celiac disease is common, but it does not always have the classic symptoms of malabsorption. It may cause only abdominal discomfort after eating, or even more vague symptoms. Most cases now can be diagnosed by blood testing. The treatment is eating a strict gluten-free diet.
Some people are unable to absorb certain nutrients. For instance, the enzymes to digest lactose and fructose frequently are missing, but lactose intolerance is much more clinically apparent. Most people recognize that symptoms occur after ingesting milk products, but sometimes the diagnosis is not clear. When not clear, the diagnosis can be made by a breath test.
Fat is another nutrient frequently not absorbed. One useful screening test for fat malabsorption is a test for fat in the feces. If present, the clinician should consider pancreatic insufficiency. The pancreas makes the enzyme critical for fat absorption.
There are many other causes, but the last one I’ll discuss is Crohn’s disease. One of the inflammatory bowel diseases, it often presents with abdominal pain and cramping, along with bloody bowel movements. However, it also might show up first more insidiously, with weight loss, with or without abdominal pain or diarrhea, due to malabsorption. An endoscopy, colonoscopy or barium study may be indicated in people with malabsorption without a clear reason for it.
FODMAPs are “fermentable oligosaccharides, disaccharides, monosaccharides and polyols.” These are hard for many people to digest, and they include fructose, lactose, gluten and some sweeteners. A low FODMAP diet is effective for many issues, especially irritable bowel syndrome, but I don’t recommend a low FODMAP diet without a thorough evaluation of the underlying symptoms. I do recommend a visit with a dietician nutritionist to go over the diet in detail.
Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to ToYourGoodHealth@med.cornell.edu or send mail to 628 Virginia Dr., Orlando, FL 32803.