The bicyclic fatty acid, lubiprostone (formerly known as SPI-0211), activates two types of anion channels in A6 cells. Both channel types are rarely observed in untreated cells. The first channel type was activated at low concentrations of lubiprostone (<100nM) in >80% of cell-attached patches and had a unit conductance of approximately 3-4 picoSiemans (pS). The second channel type required higher concentrations (>100nM) of lubiprostone to activate, was observed in about 30% of patches, and had a unit conductance of 8-9pS. The properties of the first type of channel were consistent with ClC-2 and the second with CFTR. ClC-2's unit current strongly inwardly rectified and could be best fit by models of the channel with multiple energy barriers and anion binding sites in the conductance pore. The open probability and mean open time of ClC-2 was voltage dependent decreasing dramatically with depolarization. The order of selectivity for ClC-2 was Cl>Br>NO₃>I>SCN. ClC-2 was a "double-barreled" channel favoring even numbers of levels over odd numbers as if the channel protein had two conductance pathways that opened independently. The channel could be partially blocked by glibenclamide. The properties of the channel in A6 cells were indistinguishable from ClC-2 channels stably transfected in HEK293 cells. CFTR in the patches had a selectivity of Cl> Br >> NO₃ SCN I. Because of its properties, ClC-2 is uniquely suitable to promote anion secretion with little anion reabsorption. CFTR, on the other hand, could promote either reabsorption or secretion depending upon the anion driving forces.