Acute undifferentiated human diarrhea in the tropics. II. Alterations in intestinal fluid and electrolyte movements.

The nature and magnitude of fluid and electrolyte loss into the small intestine were defined by the marker perfusion technique in patients with acute undifferentiated diarrhea (AUD) in the tropics. The patients were divided into two groups according to their small bowel bacteriologic findings, namely those with a predominant Escherichia coli flora and those with a mixed flora. 11 normal subjects served as controls. Net jejunal fluid secretion occurred into the lumen in four of seven patients with E. coli flora and three of seven with a mixed flora. The magnitude of secretion in the jejunum was greater in the E. coli flora patients than in those with a mixed flora. Four E. coli patients and one mixed flora patient had net fluid secretion in the ileum, although the magnitude of secretion in this area was less than in the jejunum. Intestinal fluid had higher bicarbonate concentration in the ileum than in the jejunum but was isotonic in both regions. It resembled in composition fluid from the same region of intestine in normal individuals. Recovery of normal fluid and electrolyte absorptive function was usually complete in both jejunum and ileum by 6-8 days after onset of the disease. Increase in unidirectional flux rates for H(3)O and (24)Na occurred in acute E. coli flora diarrhea and returned to normal levels in recovery: increase in J(beta) (plasma to lumen flux) primarily accounted for the increase in fluid loss. Intestinal biopsy revealed no alterations in villous architecture.A relationship between small bowel fluid production and the presence of toxigenic strains of E. coli within the small bowel has been found for E. coli flora patients. In many respects this disease resembles acute cholera. The mixed flora group represents a less defined entity which requires further study.