It doesn't get much more straightforward than this!
I purchased this book for a 4 year old who stubbornly refuses to try the toilet for poos but who can otherwise use the toilet perfectly well.
Too early to say if it will have an effect, but he loves this book and finds it funny.
Good that it shows the transition from nappy through to potty and onto toilet.
A few days later and success! FINALLY!!!!! First poo on the toilet.
Also used a netmums tip about getting them to blow up a balloon while sitting on the toilet. Uses the same muscles apparently.
Thanks AMAZON, a new toilet seat (cars), a few books on the subject of poo, a balloon, and the promise of a surprise (precious petzzz) if he goes has worked wonders where no amount of stickers, stars, bribes, and pleading have worked before.