Understanding the Three Main Types of Stomas
A stoma is a surgically created opening in the abdomen that allows waste — either digestive or urinary — to exit the body when the normal route is no longer possible or safe. While all stomas serve a similar purpose, there are three distinct types, each created from a different part of the body and managing a different kind of output.
If you or a loved one has recently been told that stoma surgery may be necessary, understanding the differences between these three types is an important first step.
1. Colostomy
A colostomy is formed from a portion of the large intestine (colon). One end of the colon is brought through the abdominal wall to create the stoma. Waste (stool) exits through this opening and is collected in an ostomy pouch worn on the skin.
Why is a colostomy performed?
- Colorectal cancer
- Diverticulitis or diverticular disease
- Bowel obstruction
- Traumatic injury to the bowel
- Inflammatory bowel disease (IBD)
What is the output like?
Because waste has travelled further through the digestive system, colostomy output tends to be more formed and solid — closer to what you might expect from a normal bowel movement, though this varies depending on which part of the colon is used. A sigmoid colostomy (the most common) produces the most formed output, while a transverse colostomy produces softer, more frequent output.
Colostomies can be temporary or permanent, depending on the underlying reason for surgery.
2. Ileostomy
An ileostomy is created from the ileum — the final section of the small intestine. Because the large intestine is either bypassed or removed, waste exits the body before most water absorption has occurred.
Why is an ileostomy performed?
- Ulcerative colitis
- Crohn's disease
- Familial adenomatous polyposis (FAP)
- Colorectal cancer requiring removal of the colon
- Bowel injury or obstruction
What is the output like?
Ileostomy output is liquid to paste-like in consistency, and it flows more frequently throughout the day. This means hydration and electrolyte balance are particularly important considerations for ileostomates. The output also contains more digestive enzymes, which can be irritating to the skin, making a well-fitted pouching system essential.
3. Urostomy
A urostomy (also called an ileal conduit in its most common form) diverts urine away from a damaged or removed bladder. A small segment of the ileum is used as a conduit to channel urine from the kidneys out through the stoma.
Why is a urostomy performed?
- Bladder cancer
- Severe bladder dysfunction or injury
- Pelvic cancer requiring bladder removal
- Certain birth defects or neurological conditions
What is the output like?
Urostomy output is urine — it flows continuously, so a urostomy pouch includes a drainage valve at the bottom. Many people use a night drainage bag for convenience during sleep. Staying well hydrated helps reduce infection risk and keeps the stoma healthy.
Quick Comparison Table
| Type | Source | Output | Common Reasons |
|---|---|---|---|
| Colostomy | Large intestine (colon) | Soft to formed stool | Colorectal cancer, diverticulitis |
| Ileostomy | Small intestine (ileum) | Liquid to paste-like stool | Ulcerative colitis, Crohn's disease |
| Urostomy | Ileum (as conduit) + kidneys | Continuous urine flow | Bladder cancer, bladder removal |
What Comes Next?
Regardless of which type of stoma you have or are preparing for, the most important thing to know is that life after stoma surgery can be full and rewarding. With the right information, products, and support, most ostomates return to the activities and routines they love.
Speaking with a Wound, Ostomy, and Continence (WOC) nurse is one of the best steps you can take before and after surgery — they can tailor advice to your specific type of stoma and individual needs.