I went thriugh the same thing with my daughter, we started training her in August she just turned 3, and the peeing took about a week of work for her to realize when she needed to go, but the pooping was a whole different story. She would hold it for as long as she could which in some cases was a couple days, literally until it forced itself out, but in was always in her pants-we would put her on the toilet and she would just sit there and not let it come out. I had to take her to the doctors for a check up for preschool and asked him for some ideas, his opinion was, that some kids are "scared" to poop on the toilet for whatever reason (peeing is always the easiest) he said just don't get discouraged eventhough it may be hard not to, do not make a big fuss about her not doing it and just be as encouraging as you can, he also said since she was holding it all the time that when i knew she had to go i could put a diaper on her just to let her go 9so she would not get constipated) i tried that and she was comfortable with it but i only did that a few times, i did not want it to turn into a constant thing and her never learning to go o n the toilet- the thing that got her to go, i went and bought a potty training seat (the disney princess one) and she would just sit on it etc... then she finally went one day and we praised her etc.. so then i told her every time she goes poop she could earn a dollar and that motivated her we would give her a dollar and she would put it in a clear jar on the kitchen counter (by displaying the money jar it made her "brag" about it to everyone that came over)and it made her more confident- so after 2 weeks of her going and collecting dollars i took her to the store and let her buy a toy with her "big girl" money. then had to explain that since she is a big girl now she just go potty without getting rewarded etc.. just thought i would share my experience hope it can help with some ideas for you, good luck!
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