Compounds in which 2 and R3 together with N is an azabicycloalkane or phenyl or hydroxyl substituted azabicycloalkane containing 6-9 carbon atoms and containing at least 5 atoms in each ring and wherein Ar1, Ar2, and AR3 as defined in the preceeding paragraph are particularly useful in practicing the present invention in that they are potent antidiarrheal agent with minor, if any, central nervous