I wish I had an easy answer for you. I went through this with my younger son who is now 8yrs old. It took years to get him to what we call "normal." It started with not wanting to go at all in the little potty - got rid of that right away and got him one of the seats that sit on the regular toilet. Solved the potty part and he would occasionally, if I made him sit there, poo there too. It took quite awhile to realize it wasn't so much that he was afaid to go but more that he was too busy and didn't want to take the time when he did have to go. Then either it became an emergency and he would hide or it was too hard to come out. Over time and a regular schedule of when he was going to sit there whether or not he had to go, as well plainly explaining to him that "we would wait, he won't miss anything" and "it will take longer and it will hurt if he doesn't go now" we got on the right track. It was a long hard road that we really didn't see come to a complete end until he was probably 6 1/2, maybe 7. He was doing great and relapsed into waiting too long andhaving marks in his undies. At that point he was old enough he got the hint when after several warnings and talks I started throwing them away if they were "dirty." One day he said "mom, I only have 2 pairs of underwear" and I said "yep, guess you better remember to go when you need to." Haven't had a problem since!That said, patience, consistency and a clear plan whatever that may be will help but you have to keep at it. Be willing to stick to your decisions if it involves punishment. But please, don't use cold showers or physical consequences. Personally I am not an advocate of spanking as a form of regular discipline. That's a personal choice, but at that age it is hard for them to relate the two, it is easy to confuse them. Make the consequence directly related to the problem behavior.GOOD LUCK!