I don't know about procinetic, I never heard of it. But if your food is just sitting there I have to (not meaning to get all up in your beeswax) but are you going to the bathroom regularly? If you're constipated, your food has nowhere to go and it WILL just sit there endlessly, because you are blocked further down the pike. Try a fiber supplement. I personally don't use things like metamucil etc because I don't like psyllium, it just bulks me up way too much. http://www.herbdoc.com
makes a good help Formula #1, but it can be a little strong, so if you are REALLY constipated I don't think I would recommend that. Lots of grocery stores/health food stores make fiber supplements. Just make sure you get one with no fillers/extra ingredients. Renewlife also makes a decent fiber supplement called fibersmart, but what I didn't like about their supplement, is that you had to take it three times a day (when I was really backed up and you are taking 4 pills each time you take it), that was a lot of pills to me.
Then I just started eating a lot of veggies and now it's not a problem for me anymore...
Also, I would investigate what specifically are you eating. Keep a food journal and notice what foods make you feel what.. Are certain foods worse than others?