Sugar Intolerance: Origin and Mechanisms of Symptoms?

The origin and mechanisms of symptoms in sugar intolerance were studied in 8 healthy volunteers. For two test periods, volunteers swallowed a probe with perfused catheters and an infusion catheter which migrated into the colon. A meal containing 40 g lactulose or 40 g sucrose was ingested; the sucrose meal was followed by colonic infusion of 40 g lactulose in order to bypass the small intestine. Recordings of small intestinal and colonic motility were performed. Abdominal pain, bloating, borborygmi, and flatulence were similar during both periods. Both meals increased small intestinal and colonic motility. Only 37% of the symptoms coincided in time with colonic motor events. Symptoms were not related to a specific motor event and were not correlated with breath hydrogen excretion. In conclusion, symptoms of sugar intolerance originate from the colon. They are not related to specific phasic motor events or to breath hydrogen excretion.