My 3 year old has not pooped in 6 days and i don't know what else to do?

Poop: All children have different stool patterns. If this is new, then likely constipated. At this point, there is probably bloating and a lot of gas. Increasing fluids like prune juice or giving those, figs, apricots may help. It might be difficult to use a suppository due to toddler resistance, but liquid glycerin suppositories can get things moving.