Studies on infant diarrhea. II. Absorption of glucose and net fluxes of water and sodium chloride in a segment of the jejunum.

Increased stool losses of water, solute, and organic acids after the ingestion of milk during acute diarrhea of infancy have been related to impaired absorption of carbohydrate (1). We have observed that the osmolality of diarrheal stool water is usually high during periods of milk intake. Furthermore, we have demonstrated that carbohydrate comprises most of the solute content of the stool water and that there exists a reciprocal relationship between the concentration of this compound and that of Cl-, Na+, and K+. On the other hand, there is a direct relationship between the concentration of carbohydrate and total organic anions. Similar effects of carbohydrate on stool volume and acidity have been described when specific disaccharidases are deficient (2-9) or when monosaccharide absorption is impaired (10-13). An obvious assumption is that unabsorbed carbohydrate exerts an osmotic effect in the bowel and constitutes substrate for the generation of organic acids. However, studies directed at verifying these assumptions and determining the characteristics of these processes at different levels of the small and large bowel have not been performed. Our present studies demonstrate that the absorption of glucose by the jejunum is impaired in acute diarrhea of infancy. The studies also show that the associated net movement of fluid into * the bowel in diarrhea occurs as a consequence of bulk flow, determined by excesses of glucose in the bowel lumen. Methods Ten infants with acute diarrhea (1 to 3 days' duration) who were passing liquid stools at the time they were chosen for study were investigated. In five of these, a pathogenic Escherichia coli was isolated from the stools. All were taking milk without vomiting. Once they had recovered, no recurrence of the disease was observed on follow-up examination. Seven infants who had had urinary tract infections, but who had received no medication for at least 1 month, constituted the control group. All infants were 2 to 4 months old and weighed between 4 and 6 kg. The infants were given only small quantities of water orally after 2:00 a.m. of the day of the study. Oral intu-bation of the bowel with polyethylene tubing was begun at 6:00 a.m. The tubes (Figure 1) were gently inserted through a pacifier into the stomach and allowed to progress into the bowel by gravity and peristalsis. Placement in the jejunum was verified by a spot film after bile-tinged fluid had begun to flow from the proximal …