A research paper from Israel shows that many cases of irritable bowel syndrome are caused by inability to absorb certain sugars.

Irritable bowel means that a person has terrible discomfort from intestinal gas. Sugars should be absorbed in the upper intestinal tract so they don't reach the colon. Sugars that are not absorbed, pass to the colon where bacteria ferment them to cause gas. This study shows that 78 percent of people with irritable bowel syndrome do not absorb the sugars fructose and lactose efficiently. Restricting these sugars reduced symptoms. Lactose is a double sugar in milk that has to be broken down into two single sugars, glucose and galactose, to be absorbed. If the double sugar is not split, it can't be absorbed and passes to the colon to cause gas. Most fructose cannot be absorbed until it is converted to glucose in the upper intestine. People who convert fructose to glucose slowly suffer from gas. However, avoiding fructose requires avoiding fruits which can cause nutrient deficiencies.

Only 7% of patients with IBS and 8% of patients with FC absorbed all three sugars normally. The frequency of isolated lactose malabsorption was 16% and 12% respectively. The association of lactose and fructose-sorbitol malabsorption occurred in 61% of both patient groups. The frequency of sugar malabsorption among patients in both groups was 78% for lactose malabsorption (IBS 82%, FC 75%), 44% for fructose malabsorption and 73% for fructose-sorbitol malabsorption (IBS 70%, FC 75%). A marked improvement occurred in 56% of IBS and 60% of FC patients following dietary restriction. The humber of symptoms decreased significantly in both groups (P < 0.01) and correlated with the improvement index (IBS P < 0.05, FC P < 0.025). Conclusions: Combined sugar malabsorption patterns are common in functional bowel disorders and may contribute to symptomatology in most patients. Dietary restriction of the offending sugar(s) should be implemented before the institution of drug therapy. R Goldstein, D Braverman, H Stankiewicz. Carbohydrate malabsorption and the effect of dietary restriction on symptoms of irritable bowel syndrome and functional bowel complaints. Israel Medical Association Journal, 2000, Vol 2, Iss 8, pp 583-587 Checked 8/9/05

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