Advances in our understanding of transport and epithelial functions of the colon occurred in several areas during the past year: 1) elucidation of the role of cystic fibrosis transmembrane conductance regulator in colonic chloride secretion, 2) identification of novel transport pathways for sodium, chloride, and bicarbonate in the colon, 3) delineation of the intricacies of intracellular regulation by second messengers and their surrogates, and 4) recognition of the importance of luminal and subepithelial factors in regulating and, perhaps, controlling epithelial function.