The colon The colon is an approximately 5- to 6-foot long tube that connects the small intestine to the rectum. The colon moves and processes digesting food across your body and down towards the rectum, where it exits the body as stool. There are several parts of the colon, including: Ascending colon: This section is where undigested food begins its journey through the colon. Undigested food moves upwards through this section, where fluid is reabsorbed more efficiently. Transverse colon: Moving across the body, the transverse colon takes the food from one side of the body to the other (right to left). Descending colon: Once the food has travelled across the top through the transverse colon, it makes its way downward through the descending colon—typically on the left side. Sigmoid colon: The final section of the colon, this portion is shaped like an “S” and it is the last stop before the rectum. The rectum The rectum is a 5- to 6-inch chamber that connects the colon to the anus. It is the job of the rectum to act as a storage unit and hold the stool until defecation (evacuation) occurs.