The organ responsible for digestion in humans is the gastrointestinal tract, which includes the stomach and intestines. The process begins in the mouth, where food is mechanically broken down and mixed with saliva. It then travels to the stomach, where it is further digested by acids and enzymes. The small intestine absorbs nutrients, while the large intestine reclaims water and compacts waste. This intricate system plays a vital role in converting food into energy and essential nutrients, supporting overall health and bodily functions.