I started with my daughter when she was 18 months. I cloth diapered, so she was taking off her wet diapers and I couldn't take it anymore! So, if your son understands the difference between wet and dry, is aware of when he is going, then I'd say, get started! It took us 4, almost 5 months, but by 22 months she was fully day trained, and now, at 23 months, she is fully trained, including night --yesterday she actually came running out of her bedroom in the morning to get herself to the potty on time, but she did it!
It is very possible. Also, I had a baby when my oldest was 21 months, and we moved her into a new room and big girl bed at 20 months. I did everything everyone says not to do, and let me just say, my daughter is doing great! We had a short regression when baby came, but she has adjusted to it all very well. I think it's all about giving them the confidence and giving them a lot of love.
If you are interested in doing some early start potty training, email me and I will tell you how I did it.
BTW, the natural window for potty learning is between 18-24 months old. All kids show an interest during this time, but we usually just ignore it, thanks to P
mpers and their campaign that convinced us that under two was too young. Prior to 1960, 90% of all kids (including boys) were potty trained by 18 months. So if your son knows when he needs a diaper changed, then YES, he is ready. Get started. It will take a good few months for him to learn everything, but if you ignore this window, you will only reinforce to him that it's OK to go in your pants. So while he is disgusted by the poop, teach him where it goes! Don't teach him that it's OK. It shouldn't be, if you ask me.