The digestive system breaks down food into smaller molecules that the body can use. It has two phases - mechanical and chemical digestion. Mechanical digestion involves physical breakdown of food by teeth, tongue, and muscular contractions. Chemical digestion uses enzymes to break nutrients into absorbable molecules. The major organs involved include the mouth, esophagus, stomach, liver, pancreas, and intestines. Common digestive issues include indigestion, flatulence, constipation, diarrhea, ulcers, and parasites. Proper care includes eating fiber, limiting spicy/sugary foods, chewing well, relaxing during meals, and drinking fluids.