Right side is ascending colon and left side is descending colon. It can be waste in the colon slowly moving to desending colon...slow moving....I have felt that before as well. Rub belly to help move it along...use palm (or fist, if hard) and using navel as the center, begin on the right side, upward to center and then down to the left (looking down), and around to the right. Keep doing for at least five minutes. Will help you with circulation, relieves gas/air, helps you return to good belly sounds. Do as often as possible throughout the day and you will find improvement in a very short time.
I would also suggest you get on a schedule with eating, so you can see if this pain/discomfort is in any way attributed to what you are eating. Getting on a schedule of eating something at least every 3 hours will help you maintain a working system, until you get improvement.
Eliminate sugar, carbonated beverages, alcohol....dairy, grains....try being off it for at least a month and you will see if you feel better. It may seem tough, but it is not, once you begin looking at alternatives. Good luck!