Hi, I have an almost 16 month old whom I have been trying to 'poo train', meaning whenever I catch him trying to do a poo, I will put him on the potty. This has gone well and he has peed and pooed in it willingly (but obviously a hit or miss) since he was about 11-12 months and he does seem to know when he is about to poo. He acts urgent and bends over, starts straining. However recently, my sweet boy has completely changed into whiney, tantrumy boy (Constantly!). He has also suddenly refused to go in the potty, refusing to sit for longer than a few seconds, standing up and telling me he is done. It sounds unusually stubborn at this age, but he either holds on until I put the nappy back on and then he pees and poos in it, or he holds it for 2 days (if I put him on each time I see him straining) and he gets constipated and finally does it in his nappy anyway when I'm not around. Much like what I hear from my friends potty training their children at 2+! His sister was poo-trained in the same way and was done with poo training (with very occasional accidents) by 18 months. She was not quite as headstrong over it at this age. I'm wondering what your advice would be about this, given that it is not the lack of ability but the complete refusal to poo in the potty. Wilfulness. I have a feeling his refusal of it will be even stronger by 18 months. What should I do? Wait anyway?