Researchers say they have discovered an entirely new class of life inside the human body, and it is very similar to a virus.

The digestive system is the series of tubelike organs that convert our meals into body fuel. There are about 30 feet (9 meters) of these convoluted pipeworks, starting with the mouth and ending ...

The digestive system comprises several organs, all working in concert to turn the food you eat into energy. But sometimes, illness or injury can lead to a digestive disease that threatens your ...