M.B.
My son went for almost a year without pooping in the potty. He would go hide and then waddle out almost in tears. He could not poop sitting down. He finally started standing at the toilet and he would poop. I have no idea how he did it without making a mess, but it was the funniest thing to see. He is now 9 and can do it sitting down. My daughter wouldn't go so we put cheerios in the potty and told her she needed to count how many she could hit. I put pull ups where she could reach them and let her put one on if she felt she needed to. If she went in the toilet she got a sticker, if she went in a pullup she lost a sticker. When she got to a certain amount of stickers, she got a treat. It's a long process, but just be patient and be consistent. Don't ever get angry if she goes in her pants. It will just prolong the process.