DS2, nearly 4, was potty trained, but since an anal fissure at Christmas has now regressed and has not pooed on the toilet or potty since. He hides and poos in his pants, up to three times a day. I have tried patience, encouragement, bribery and, more recently (in desperation) meanness (I have told him that he can't go to big school until he can do it on the toilet). Nothing has worked. He was on lactulose for several months, but that didn't make a difference (just made the cleaning up stickier). I am going to take him to the doctor's again, but wondered if anyone had had any success with type of problem.