COLONIC PERFUSION STUDIES IN CONGENITAL CHLORIDE DIARRHOEA

Abstract

Congenital chloride diarrhoea, an autosomal recessive disease characterized by hydramnios and persistently watery stools with high Cl- concentration has been described in 17 patients outside Finland. We have seen 17 cases of which 14 are still alive and doing well. The basic defect of this disease has been postulated to be an inability to absorb Cl- in the distal ileum and possibly in the colon. We have studied 3 patients and 3 healthy siblings to determine the presence and nature of the colonic electrolyte transport defect. A double lumen perfusion tube was brought into the proximal colon and fluid was collected 10 cm from the infusion point and from the anus. Polyethylene glycol was used as a nonabsorbable marker for water movement and 36 Cl to measure influx and outflux of Cl-. Perfusions with a physiological salt solution showed no difference from controls in Na+ absorption but with Na+ concentration of 24 mM the CCD-patients showed secretion in contrast to absorption in controls. K+ and H+ were secreted at markedly higher rate in CCD. Controls absorbed Cl- from luminal concentration as low as 15 mH whereas CCD-patients absorbed Cl- only in minimal amounts and from luminal concentration of over 70mM. Bicarbonate secretion was probably masked by/H+ secretion in CCD. Deficient Cl- absorption is probably the primary defect and increased sedretion of K+ and H+ is a secondary phenomenon.