&NA;Advances in understanding the mechanisms of epithelial transport in the colon have consisted of both a narrowing and a broadening of the focus of investigation. Researchers have homed in on the structure of the protein associated with the specific genetic defect of cystic fibrosis and are now manipulating discrete regions of the protein to determine changes in function. New methodology permits investigators to characterize the behavior of individual channels and their mechanisms of regulating ion transport. Another approach has broadened our view of regulation of colonic transport beyond the epithelial cell and examined the role of the immune system and the enteric nervous system in modulating epithelial function. Not only sodium, potassium, and chloride are transported by the colon; investigations of short‐chain fatty acid and mucus transport provide some insight into the complex functions of the colon.Current Opinion in Gastroenterology 1992,8:5‐11