The presence of increased inherent or acquired
mucosal permeability in IBD would have several important
effects on absorptive function, particularly
in the distal small intestine and colon, where the
epithelial layer must be “tighter” to prevent backflux
of absorbed water and electrolytes. Potential
difference-dependent passive absorption of electrolytes
would also be diminished because potential difference
is a product of electrogenic ion flux and mucosal
resistance (the latter being decreased in
inflamed areas of bowel).