Carbohydrate intravenous tolerance

The tolerance of normal humans for the oral administration of lactose is considerable. Urinary excretion takes place mainly after hydrolysis to D-glucose and D-galactose. When the sugar is injected intravenously into rabbits, it is excreted unchanged 73). Rats are unable to survive on a diet in which lactose is the sole source of carbohydrate they develop diarrhea and alopecia and finally die 74). (For more discussion, see Chapter XIV.)... 

Intravenous glucose tolerance test. This is used for investigating glucose metabolism when abnormal carbohydrate absorption is present. 

It may be necessary to eliminate the carbohydrate in the diets of patients on oral feedings until diarrhea has been brought under control. In these cases, the minimum requirement for sugar (glucose) may be met by Intravenously administered solutions of dextrose. Usually, the ability of the patient to tolerate carbohydrates Improves as malnutrition is corrected and the damaged intestinal lining Is healed. Sometimes, wheat protein (gluten) is tolerated poorly and has to be eliminated from the diet. 

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