Hello!
My daughter had the same problem. She would pee on the potty, but was terrified to poop on the potty. She would just walk around the house on her tip-toes holding it in if she wasn't in a Pull-Up or diaper. The "holding" would cause constipation and pain, and we didn't know what to do. She would walk around the house crying from trying to hold it in and knowing it was going to hurt when it came out (because of the constipation.) We tried potty charts and promises of treats and toys. Even the teachers at pre-school were willing to drive to the grocery store and come back with a cake just for her if she would poop on the potty, but no such luck. She wasn't going for it. We even considered hypnosis (too expensive) or taking her to a child psychologist to see if they could "cure" her fears. We were truly at our wits end!
When she was three years old we took her to a pediatric gastroenterologist to see if there was something that could be done about the holding and horrible constipation that resulted. The Specialist said there are two things you cannot make a child do...eat and poop. She said the more you emphasize the issue, the worse it will become. It will turn into a power struggle that you won't win. She said it is up to the child as to when they feel comfortable pooping on the potty. Until that time, she said not to focus on the issue and allow the diapers/Pull-Ups (only when Maddie asked for them). She said the only thing we could do is make sure the poop was soft when she did decide to finally go. We tried all of the normal remedies (apple juice, prune juice, high-fiber foods, etc.), but nothing seemed to work for her. The Specialist recommended daily doses of MiraLax (one capfull in the morning and one capfull in the evening).
On August 21, 2009 (a day that will live in infamy in our house), my husband and I were in the living room and she started calling my name. I asked what she needed and she announced that she just pooped on the potty and needed me to wipe her. My husband and I both JUMPED up and RAN to the bathroom. Sure enough, there she was, sitting there grinning from ear to ear. We all cheered and clapped. It was crazy!! We called and texted people to tell them the good news...seriously, this was a HUGE accomplishment! She said she just decided to try pooping on the potty. She saw there was nothing to be afraid of and hasn't stopped since!
Maddie was 4-1/2 years old when it FINALLY happened, so just be patient. The Specialist said it is not uncommon problem and there are even some kids in Kindergarten that hold it all day and come home and ask for a Pull-up. Hopefully, yours won't get to that point...since it does become hard to find diapers/Pull-ups to fit them as they get older.
MiraLax has been a lifesaver for us and I know it will work for you. It is a white powder that can be mixed into any drink. It dissolves completely and has no taste. It is safe for all ages, it is not addictive and you cannot overdose on it (per the Specialist.) It is not a stimulant, so it will not cause tummy aches or cramping. It just causes the body to hold more water in the stool making it softer and easier to poop. Once you start giving it to her, it will take two to three days for results. Just be consistent with the doses and he will feel much better. You can also find generic versions of it at Walmart, CVS and Walgreens. I checked with the Specialist and she said the generic versions were just fine (and cost quite a bit less!)
If you want to talk or have any question, please feel free to e-mail me. I know how frustrating this can be.
A.