Try to drink more water. A good rule of thumb is to drink one fluid ounce of water for every two pounds of your body weight. For instance, if you weigh 100 pounds, drink at least 50 ounces of water each day.
You could also give yourself a visceral massage (called Sun-Moon). To begin, lie on your back and with both hands starting just above your right hip, apply inward pressure on your abdomen, going straight up to the bottom of your rib cage. Then follow along the bottom of the rib cage to the left and then down to the top of the left hip. Go slow and repeat to tolerance.
Another option is to try Hydro Colon Therapy. Also know as colonic irrigation, it is a highly effective, although somewhat uncomfortable, method of flushing out the colon, or large intestine. Similar to an enema but more extensive, this procedure can be pricey (it has to be done by a trained professional).
An alternative to this is the Natural Colon Cleanse. A less invasive option is to find a good, all natural colon-cleansing product. Many of the new formulations taste OK, work gently, and cause no cramping or bloating. Most of these products begin to work overnight. The better products come with an anti-parasitic and an herbal tea.