Sugar Malabsorption

     Fruit juices are high in sugars including fructose and sorbitol. This can result in digestive upset and diarrhea in susceptible individuals. Sorbitol inhibits absorption of fructose. Unabsorbed sugars feed bacteria which can overgrow damaging the lining of the digestive tract and leading to diarrhea. Infants and children are particularly susceptible to this problem. Parents should be cautious when feeding young children high sugar fruit juices.

     In a study of patients with irritable bowel syndrome only 7% of patients absorbed lactose, fructose, and sorbitol normally. Those with functional bowel complaints scored little better (8%). About three-quarters of the patients in both groups tolerated lactose (milk sugar) and a fructose-sorbitol combination poorly. Well over half of the patients improved with restriction of sugar intake. The researchers concluded, "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." Sometimes the solutions are simple if people only knew.

Perman, Jay A., M.D., Digestion and Absorption of Fruit Juice Carbohydrates,

Journal of the American College of Nutrition, 1996;15(5):12S-17S.

Goldstein, R., et al., Carbohydrate malabsorption and the effect of dietary restriction on symptoms of irritable bowel syndrome and functional bowel complaints, The Israel Medical Association Journal : IMAJ [2000, 2(8):583-587]