Here, the veteran author and physician gives all the information needed to understand how digestion works and what foods will bring about a healthy digestive system. Dr. McDougall is one of the country's foremost advocates for the use of diet to prevent and treat chronic illness. The right dietary choices can prevent, treat, and—in some cases—completely eliminate a host of digestive disorders including acid reflux, colitis, colon polyps, high blood pressure, cholesterol, ulcers, constipation and gallstones.