Complex carbohydrate malabsorption in exocrine pancreatic insufficiency

The magnitude of complex carbohydrate malabsorption in exocrine pancreatic insufficiency has not been well quantified in the past. The quantity of carbohydrate malabsorbed after a rice starch (100 g) meal in 20 patients with chronic pancreatitis (n = 10) or pancreatic cancer (n = 10) was therefore estimated. Patients had a three day stool fat collection (80 g/24 hour fat intake), a lactulose (20 g), and a rice flour (100 g) breath hydrogen test. Normal controls (n = 29) had a postprandial H2 increase < or = 14 ppm and malabsorbed (mean (SEM)) 1.12 (0.44) (range 0-11.10) g of the 100 g of carbohydrate ingested. Patients malabsorbed significantly more carbohydrate (11.36 (2.23) (range 8.90-32.60) g, F1.47 = 29.92, p < 0.001). The number of patients with fat (> 7 g, n = 8) or carbohydrate (increase in H2 > or = 20 ppm, n = 10) malabsorption was not different (chi 2 = 0.10, p = 0.75). There was a significant correlation between faecal fat and amount of malabsorbed carbohydrate (r = 0.60, F1.17 = 9.70, p = 0.006) and faecal fat and stool wet weight (r = 0.57, F1.18 = 8.67, p < 0.009), but not between stool wet weight and amount of malabsorbed carbohydrate (r = 0.28, F1.17 = 1.45, p = 0.25). Although patients with exocrine pancreatic insufficiency malabsorb 10%-30% of the ingested complex carbohydrate, the main determinant of stool wet weight could be faecal fat.