Some short-chained carbohydrates can result chronic diarrhea, abdominal bloating, gas, or other gastrointestinal indications in individuals, who already have been diagnosed:
- Dyspepsia (indigestion)
- Irritable bowel syndrome (IBS) or functional bowel disease (FBD)…
- Celiac disease
- Dumping syndrome (rapid gastric emptying)
- Fructose malabsorption
- Inflammatory bowel disease (Crohn's disease, ulcerative colitis)
- Lactose intolerance
- Small intestinal bacterial overgrowth (SIBO)
What are FODMAPs?
FODMAPs (Fermentable Oligo-, Di-, and Mono-saccharides, And Polyols) are short-chain carbohydrates that are Osmotically active, and may remove water from intestinal vessels into intestinal lumen, thus resulting diarrhea and/or easily degradable (fermentable) by intestinal bacteria, and producing large amount of gases like hydrogen, carbon dioxide, or methane thus resulting in bloating
FODMAPs include:
Oligosaccharides: Fructans that are the chains of fructose with glucose molecule on the closing. Only minimum quantities of fructans are possibly absorbed in human intestine. They may intervene with fructose absorption, resulting in worsening the symptoms in fructose malabsorption. Wheat (white bread, pasta, pastries, cookies), onions, and artichokes are Fructane-rich foods. Foods like asparagus, leeks, garlic, chicory roots, and chicory based coffee substitutes contain fructanes but are not commonly problematic. Inulins are the Fructans with over 10 molecules of fructose in a chain. and those with less than 10 fructoses are referred (on food product labels) as fructo-oligosaccharide (FOS) or oligofructose. Fructans cause problems mainly in fructose malabsorption.
Galactans(like stacchyose and raffinose) are chains of fructose with galactose molecule on the end. They act much like fructans. Galactans-rich foods are legumes (soy, beans, chickpeas, lentils), cabbage, and brussel sprouts.
Disaccharides:
Lactose (milk sugar). Lactose is in dairy products, but may be also found in chocolate, and other sweets, beer, pre-prepared soups and sauces, etc. Lactose is poorly absorbed in lactose intolerance, SIBO, and in small intestinal inflammation (Crohn's disease, celiac disease).
Monosaccharides:
Fructose (fruit sugar). Fructose-rich foods are honey, dried fruits like prunes, figs, dates, or raisins, apples, pears, sweet cherries, peaches, agave syrup, watermelon, papaya, etc. Fructose is often added to commercial foods and drinks as high fructose corn syrup (HFCS). Fructose causes symptoms even in healthy people, if ingested in excess, especially in fructose malabsorption, but also in SIBO.
Polyols, also known as sugar alcohols (appearing as artificial sweeteners in commercial foods and drinks):
- Sorbitol may appear in "sugar-free chewing gum", "low calorie foods"; naturally it appears in stone fruits: peaches, apricots, plums, etc).
- Xylitolnaturally apears in some berries. A pack of chewing gum containing sorbitol or xylitol may cause symptoms in a healthy child, and especially in persons with fructose malabsorption or SIBO.
- Other polyols:mannitol, isomalt, erithrytol, arabitol, erythritol, glycol, glycerol, lactitol, ribitol, etc may be problematic in fructose malabsorption, and in SIBO.
Possible Symptoms of FODMAP-Rich Diet
Excessive FODMAPs ingestion may cause:
- Diarrhea, since they are osmotically active, so they drag water from intestinal vessels into intestine
- Bloating and flatulence, since they are broken down (fermented) by intestinal bacteria into gases like hydrogen, carbon dioxide, or methane
- Abdominal pain
- Unintentional weight loss
- Symptoms of vitamin and mineral deficiency
- Headache, lethargy, and depression.
Approach to Low-FODMAPs Diet
In unexplained chronic diarrhea or bloating, FODMAPs should be considered as a possible cause, so their amount in the diet should be LIMITED (not necessary totally excluded).
General approach is to take off as much as possible FODMAPs from the diet for six-eight weeks. If FODMAPs are the cause of the symptoms, these should lessen considerably in the first week. Additional weeks of diet bring some rest to the small intestine, and cause reduction of overgrown intestinal bacteria.
After six weeks, some foods that will least likely cause symptoms can be introduced back into the diet (diet challenge), one type of food every fourth day. For example, on the first day of the seventh week, a piece of lactose containing food like cheese can be tried, and if in the next 72 hours no symptoms appear, additional amount of cheese or other dairy can be tried, and waited 72 hours again. If still no symptoms, it's likely that dairy is not problematic food, or at least not problematic when taken in limited amount. If symptoms appear, this speaks for lactose intolerance, so dairy should be avoided and next type of foods tried. This can be some low-fructosefood like banana, then after 72 hours orange, and so on foods with increasing amount of fructose. If someone can eat 5 prunes, it's not likely that he/she has fructose malabsorption.
A registered dietitian may be needed to give instruction about introduction of the low-FODMAP diet and diet challenge.
How Long Should a Low-FOODMAP Diet Last?
When problematic FODMAPs are identified, some persons will need to strictly avoid them for life, if they wants to be symptoms free, others will be able to ingest them in limited amount after weeks of diet. General rule is: not eat FODMAPs-rich foods in great amount in one sitting, and not eat them every day.
If Low-FODMAP diet doesn't help, testing for food allergies, dumping syndrome, celiac disease, and inflammatory bowel disease (Crohn's disease) should be considered.
Can Low-FODMAP Diet be Dangerous?
Low-FODMAP diet should not be introduced by any person with diabetes, hypoglycemia or other metabolic disorders, or in malnutrition, without prior consultation with a doctor. It may be necessary to interrupt Low-FODMAP diet in any severe acute disease, after injury or surgery, and in other urgent situations.
None of FODMAPs (fructans, galactans, fructose, lactose, polyols) is essential nutrient for human though, meaning they are not necessary for life.
Foods to Avoid in IBS
Foods that irritate individuals diagnosed with IBS, differ from person to person. It was found out that in many of them FODMAPs-rich foods are the culprit (1).
