How your digestive system works
An ileostomy creates a major physical change for a patient, but it doesn’t really change the digestion of food or body chemistry. To understand how an ileostomy works, it helps to know how the digestive tract normally works (see Figure 1).
After food is chewed and swallowed, it passes through the esophagus (swallowing tube) into the stomach. From there it goes into the small intestine. Hours can go by before it moves into the large intestine or colon. After hours or even days, it leaves the storage area called the rectum by way of the anus. For most of its passage, the food is liquid and loose. Water is absorbed in the colon, causing the stool to become a firm mass as it nears the rectum.
The small intestine
The small intestine is the longest section of the digestive tract. Food nutrients are digested and absorbed here as food is moved through by peristalsis. (Peristalsis is the wave-like muscle contractions that move food through the digestive tract.)
The small intestine is about 20 feet long. It’s made up of 3 sections:
- Duodenum (first part) – 10 to 12 inches beginning at the outlet of the stomach
- Jejunum (second part) – about 8 to 9 feet
- Ileum (third part) – about 12 feet, it connects to the colon at the cecum
The small intestine lies loosely curled in the belly (abdominal cavity).
The large intestine
The large intestine (also called the large bowel) joins the small intestine where the ileum and cecum meet on the body’s right side.
The colon is by far the biggest part of the large intestine. It’s about 5 to 6 feet long, and is made up of these sections:
- Cecum –the entry point for food that has been through the small intestine and is now a highly acidic liquid. It contains a valve that keeps food from going back into the small intestine.
- Ascending colon – the contents are acidic liquid. This section goes up the right side of the body.
- Transverse colon – the contents are less acidic liquid. This section goes across the belly.
- Descending colon – the contents become more formed. This section goes down the left side of the body into the pelvis.
- Sigmoid colon – the contents are usually solid. The sigmoid is an S-shaped curve at the end of the descending colon, just above the rectum.
The main jobs of the colon are absorbing water and electrolytes (salts and minerals the body needs, like sodium, calcium, and potassium), moving stool, and storing waste until it’s passed out of the body.
The rectum and anus
The rectum is the last part of the large intestine that connects the sigmoid colon to the anus. Normally at this point the bowel contents are solid. Special nerve pathways to the brain make us aware when the stool reaches the rectum. As stool enters the rectum, we feel the need to have a bowel movement. The anal sphincter muscle is like a valve that allows us to control this. Unlike the rest of the digestive tract, it closes (contracts) or opens (relaxes) at our will to allow stool to pass out of the body.
- What is an ileostomy?
- How your digestive system works
- Types of ileostomies
- Managing your ileostomy
- Choosing an ileostomy pouching system
- Emptying and changing the ileostomy pouching system
- Ordering and storing ileostomy supplies
- Caring for an ileostomy
- Avoiding and managing ileostomy problems
- If you are hospitalized while you have an ileostomy
- Living with an ileostomy
- Telling others about your ileostomy
- What to wear when you have an ileostomy
- Eating and digestion with a ileostomy
- Returning to work after getting an ileostomy
- Intimacy and sexuality when you have an ileostomy
- Playing sports and staying active with an ileostomy
- Traveling when you have an ileostomy
- For parents of children with ileostomies
- Getting help, information, and support
- To learn more
In its original form this document was written by the United Ostomy Association, Inc. (1962-2005) and reviewed by Jan Clark, RNET, CWOCN and Peg Grover, RNET. It has since been modified and updated by:
Last Medical Review: December 2, 2014 Last Revised: December 2, 2014