When we consume food, it is not in a form that the body can directly use as nourishment. It must be converted into smaller molecules of nutrients, which can then be absorbed into the blood and carried to cells throughout the body, providing the necessary fuel to function. This is the job of the digestive system: a series of organs joined by a long, twisting tube that runs from the mouth to the anus.
Food enters the esophagus through the mouth. The esophagus connects the throat and the stomach. There is a ring-like valve where the esophagus meets the stomach, which relaxes to allow food to pass into the stomach before closing up again. The stomach stores the food and liquid, then mixes it all up with digestive juices. The walls of the stomach and the digestive system's other major organs contain muscles, which enable them to move, propelling food and liquid through the digestive tract by squeezing itself like a wave. This is called peristalsis.
Once the stomach has emptied its contents into the small intestine, the partially digested food is dissolved even further by juices produced by the pancreas, liver and intestine. Then it is mixed and pushed along even further as nutrients are absorbed through the intestinal walls into the bloodstream. Waste products include undigested parts of food, like fiber, as well as older cells that have been shed from the intestinal walls. These are passed into the colon before being excreted by the body.
How do you know if you might have irritable bowel syndrome? If you have crampy abdominal pain with painful constipation and/or diarrhea, ask your doctor.