Bile acids are classically known for their roles in facilitating fat digestion and absorption but more recently they have become appreciated as “enterocrine hormones” that regulate many other aspects of intestinal physiology, including immune responses, epithelial barrier function and electrolyte secretion. Recently, we have shown that activation of the nuclear bile acid receptor, Farnesoid X Receptor (FXR), chronically inhibits colonic fluid and electrolyte secretion. However, nuclear receptors are also known to have the capability to exert rapid onset, non-genomic, actions. Thus, in current study we aimed to determine if FXR activation exerts rapid effects on colonic Cl- secretion. Methods: GW4064 (5 μM) and INT-747 (30 μM) were used to activate the FXR. Cl- secretion was measured as changes in short-circuit current (Isc) across T84 cell monolayers mounted in Ussing chambers. FXR expression was measured by immunoblotting. Data are presented as mean ± SEM and were statistically analysed by ANOVA or Student t-test, as appropriate. Results: FXR activation did not alter basal fluctuations in Isc which were 3 ± 1 μA/cm2 compared to 4 ± 1 μA/cm2 in control cells (n = 13). However, following 15 min treatment with the non-steroidal FXR agonist, GW4064, Cl- secretory responses to the cAMP-dependent agonist, forskolin (FSK, 10 μM) were decreased to 82 ± 8% (n = 13, p < 0.05) of those in control cells. In comparison, GW4064 did not alter responses to the Ca2+-dependent agonist, carbachol (CCh) (n = 13). Inhibition of cAMP-dependent secretory responses was sustained for 2 hrs, by which time they were reduced to 65 ± 9% of control responses (n = 4, p < 0.001). However, antisecretory actions of GW4064 were no longer apparent after 6 hrs when responses to FSK were 94 ± 4% of those in control cells (n = 3). FXR expression in the nucleus was not significantly increased for as long as 3 hours of GW4064 treatment (n = 4), which indicate that the acute actions of GW4064 are non genomic. Interestingly, a structurally distinct FXR agonist, INT-747 exerted similar effects to GW4064. cAMP-dependent Cl- secretion in INT-747-treated cells was significantly attenuated to 48 ± 5% of control responses (n = 8, p < 0.01). Conclusions: This study reveals novel rapid responses to activation of the nuclear bile acid receptor, FXR, in colonic epithelial cells. FXR activation rapidly, and specifically, downregulates responses to cAMP-dependent secretagogues and these non-genomic effects may contribute to antisecretory actions of FXR agonists in the colon.