The oesophagus is also known as the gullet or food pipe. It’s part of the digestive system, which is sometimes called the gastro-intestinal tract (GI tract). The oesophagus is a long, muscular tube that connects your mouth to your stomach.
It’s around 25cm (10in) long in adults. When you swallow food, the walls of the oesophagus squeeze together (contract). This moves the food down the oesophagus to the stomach.
The colon and rectum are part of your intestines, which are long, hollow tubes that run from your stomach to your anal opening. There are two types of intestines: the small intestine (or small bowel) and the large intestine (also called the colon or large bowel). The small intestine connects your stomach to your colon, and your colon then attaches to your rectum and, ultimately, your anus. The colon is about five to six feet long and about an inch or two in diameter.
The pancreas is a long flattened gland located deep in the belly (abdomen). Because the pancreas isn't seen or felt in our day to day lives, most people don't know as much about the pancreas as they do about other parts of their bodies. The pancreas is, however, a vital part of the digestive system and a critical controller of blood sugar levels.