Congenital chloride-losing diarrhoea: absence of the anion-exchange mechanism in the rectum.
BACKGROUND
Congenital chloride-losing diarrhoea is characterized by a defect in chloride/bicarbonate exchange, which is normally present in the ileum and colon. Whether the defect is an absence or a reversal of such an exchange is unclear, and we have investigated two young children with the disorder to answer this question.


METHODS
We used a previously described nonequilibrium rectal dialysis method, using different dialysate anion concentrations, to investigate the movement of sodium, potassium, chloride, and bicarbonate in the rectum of the two children.


RESULTS
The results showed that chloride and bicarbonate movements were not linked in any active way, and both ions appeared to move passively in response to the electrochemical gradients generated.


CONCLUSIONS
In the two subjects studied, the defect in the rectum appears to be an absence of the normal anion exchange mechanism present in the bowel, rather than its reversal.
Jenkins
H R
HR
Institute of Child Health, London, England.
Milla
P J
PJ
D001639:Bicarbonates / Q000378:metabolism; D002675:Child, Preschool; D002712:Chlorides / Q000378:metabolism*; D003956:Dialysis; D003967:Diarrhea / Q000151:congenital* / Q000378:metabolism; D004573:Electrolytes / Q000378:metabolism*; D006801:Humans; D007223:Infant; D011188:Potassium / Q000378:metabolism; D012007:Rectum / Q000002:abnormalities / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism
D001639:Bicarbonates; D002712:Chlorides; D004573:Electrolytes; D012964:Sodium; D011188:Potassium