This invention provides a method of treating or inhibiting colonic polyps in a mammal in need thereof which comprises administering to said mammal a compound having the formula ##STR1## wherein: X is phenyl which is optionally substituted; R and R.sub.1 are each, independently, hydrogen, halogen, alkyl, alkoxy, hydroxy, or trifluoromethyl; R.sub.2 is hydrogen, alkyl, alkoxy, hydroxy, trifluoromethyl; Y is a radical selected from the group consisting of ##STR2## R.sub.3 is independently hydrogen, alkyl, carboxy, carboalkoxy, phenyl, or carboalkyl; n=2-4; or a pharmaceutically acceptable salt thereof, with the proviso that each R.sub.3 of Y may be the same or different.