Toilet....Hamper.....Whatever

We have been potty training Samson for over a week now. I first tried a few weeks ago, but we went through 9 pairs of underwear in 3 hours, and we were both very stressed by then. I felt so defeated I never wanted to try it again. But then he kept going peepee in the potty for his daddy after bath time, so I decided to give it another try. He's been doing great. We've had a handful of peepee accidents, but day after day it gets easier and easier. I bought a portable potty that fits easily in our diaper bag, it works great. The only hang up we're really having is that I think Samson must be afraid to go poop in the potty. He's been holding it and making himself constipated. I gave him a ton of grapes the other day to help him along, and it worked. He had just gone peepee and ran out of the bathroom without his underwear on and climbed into his froggy hamper and closed to lid. Moments later he was crying so I ran over thinking he had somehow gotten stuck. But when I open the lid and lifted him out I saw a foot long poo sitting on the bottom of his hamper! Nasty!! Thank goodness I had just done laundry and it was empty! I could post a picture, but I'll spare you! ;)