Don't be worried about the pooping if he's eating and otherwise seems fine. They don't poop every day, every few days or even about once a week or so is normal. Getting his tank warmer will help him digest his food and humidity will help him pass it along. If you're gone during the day I would get a repti-fogger, they cost about 40-60 dollars but are well worth it, you can use it alone or get a timer for it to keep the humidity where it should be.