Colonic hypersensitivity induced by either early life stress is ameliorated by inhibition of RET kinase with GSK3179106. Rats dosed with GSK3179106 for 3.5 days twice a day exhibit an attenuated visceromotor response to colonic distension after colonic hypersensitivity was induced by exposure of rats to limited nesting stress (n = 7 to 8/group), a form of early life stress (A), and by exposure to maternal separation (n = 6/group), another form of early life stress (B). (C) In comparison with rats exposed to limited nesting stress and orally dosed with vehicle (n = 8), rats dosed with doxantrazole (n = 8), a mast cell stabilizer, have a reduced visceral motor response to colonic distension. **P < 0.01; ***P < 0.001; ****P < 0.0001 vehicle compared with GSK3179106 treatment, two-way RM-ANOVA, and Bonferroni’s post-test.