A stoma is a surgically created opening on the surface of your abdomen that allows waste to leave your body through an alternative route. During the procedure, a surgeon brings a section of your intestine (or, in some cases, your urinary tract) through the abdominal wall so it opens directly onto your skin. The opening itself is the stoma; the surgery that creates it is called an ostomy.
How a Stoma Looks and Feels
A healthy stoma is pink or red and looks like moist tissue, similar to the inside of your mouth. It’s round or oval, slightly raised above the skin surface, and warm to the touch. One detail that surprises many people: a stoma has no nerve endings. You won’t feel pain or sensation in the stoma itself, though the skin surrounding it can be sensitive.
Stomas vary in size. Right after surgery, swelling makes the stoma larger than it will eventually be. Over the first six to eight weeks, it gradually shrinks to its permanent size. During this period, you’ll need to adjust the fit of your pouching equipment as the stoma changes shape.
Three Main Types
The type of stoma you receive depends on which part of the body needs to be bypassed.
- Colostomy: A portion of the large intestine (colon) is brought to the surface, usually on the left side of the abdomen. Because the colon has already absorbed most of the water from digested food, the output is generally firm, similar to a normal bowel movement.
- Ileostomy: The end of the small intestine (ileum) is brought to the surface, typically on the lower right side. Since food hasn’t yet passed through the colon, the output is more liquid or paste-like. Diet and the amount of remaining small intestine both influence consistency.
- Urostomy: The tubes that drain urine from the kidneys are rerouted to an opening on the abdomen, bypassing the bladder entirely. A small segment of the small intestine is used to form the stoma, so the urine that passes through it may contain some mucus.
Why Someone Might Need a Stoma
A stoma is created when part of the digestive or urinary tract can no longer function safely. The most common reasons include colorectal cancer (especially when the rectum must be removed), inflammatory bowel disease such as Crohn’s disease or ulcerative colitis, and complications from diverticulitis, including infection or severe bleeding that requires bowel surgery.
Other conditions that can lead to a stoma include a partial or complete bowel blockage, traumatic injury to the colon or rectum, birth defects like a blocked or missing anal opening, and abnormal connections (fistulas) between internal organs or between an organ and the skin.
Temporary vs. Permanent
Not every stoma is lifelong. Many are created as a temporary measure, giving a damaged or surgically repaired section of bowel time to heal. Once healing is confirmed, a second surgery reconnects the intestine and closes the stoma. Most reversals are planned six weeks to six months after the original operation, though the exact timing depends on how well recovery is going.
A reversal isn’t always possible. Surgeons may advise against it if the bowel hasn’t healed well, if there isn’t enough healthy intestine left to reconnect, if the anal sphincter muscles are too weak (which would risk incontinence), or if the original disease has returned. In those situations, the stoma becomes permanent.
How the Stoma Site Is Chosen
Placement matters more than most people realize. Before surgery, a specialist nurse examines your abdomen in multiple positions: standing, sitting, lying down, and bending forward. This reveals skin folds, creases, and scars that could interfere with getting a secure seal on the pouching equipment afterward. The goal is a flat surface within the rectus abdominis muscle (the vertical muscle running down the center of your abdomen) where the pouch can adhere reliably.
You’ll be asked to remove clothing over your abdomen so the team can see where your waistband sits, since the stoma is ideally placed below the belt line so a pouch stays hidden under everyday clothes. The team also confirms that you can see the site yourself, which makes self-care easier once you’re managing things at home.
The Pouching System
After surgery, waste exits through the stoma continuously or periodically, depending on the type. Since a stoma has no muscle to control when output passes, an external pouching system collects everything. The setup has two core components: an adhesive skin barrier that sticks to the skin around the stoma, and an odor-proof pouch that attaches to that barrier and holds the output.
Pouching systems come in one-piece and two-piece designs. In a one-piece system, the skin barrier and pouch are fused together and replaced as a single unit. In a two-piece system, the skin barrier stays on your skin and connects to the pouch through a plastic ring called a flange, letting you swap out the pouch without peeling off the adhesive each time.
Pouches themselves come in drainable and closed-end varieties. Drainable pouches have an opening at the bottom that you unseal to empty, then reseal. These work well for ileostomies, where output is frequent and liquid. Closed-end pouches are discarded when they’re about half full and tend to suit colostomies with firmer, less frequent output. Skin barriers can be pre-cut to a standard round size or cut-to-fit, which lets you customize the opening to match your stoma’s exact shape.
What Normal Output Looks Like
Right after surgery, it’s typical to have no stoma output for the first two to three days. Gas usually comes first, followed by very loose stools as the bowel wakes up. This gradually firms up, especially with a colostomy, as your digestive system adjusts.
For a colostomy, a typical daily output ranges from about 200 to 700 milliliters (roughly 1 to 3 cups), though some guidelines put the upper end closer to 900 milliliters. Ileostomy output tends to be higher and more liquid. Output above 1.5 to 2 liters per day is considered high and can lead to dehydration, while output below about 200 milliliters per day is unusually low and could signal a blockage.
Common Complications
Skin irritation around the stoma is the most frequent problem, affecting roughly 14% of people with a loop ileostomy and up to 32% of those with a loop colostomy. The irritation usually results from output leaking under the skin barrier or from an allergic reaction to the adhesive. Keeping the barrier well-fitted to the stoma’s size is the most effective way to prevent this.
Parastomal hernia, where abdominal tissue bulges through the muscle around the stoma, is the other major concern. It’s especially common with end colostomies, where reported rates are notably high. Supporting the abdominal wall during physical activity and avoiding heavy lifting in the months after surgery can reduce the risk.
Stoma prolapse, where the intestine pushes further out through the opening than intended, is less common but more likely with loop colostomies. Most prolapsed stomas can be managed without additional surgery, though severe cases may need surgical correction.