Basics
The Types of Ostomy Explained
A clear, clinical guide to colostomy, ileostomy and urostomy — how each type works, why it is formed, and what to expect in daily life.
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An ostomy is a surgically created opening — called a stoma — that allows waste products (stool or urine) to leave the body through the abdominal wall rather than through the usual anatomical route. Ostomies are performed for a wide range of reasons, including cancer, inflammatory bowel disease (IBD), trauma, diverticular disease, and congenital conditions. Understanding the different types is the foundation of confident, informed self-care.
The Three Main Types of Ostomy
There are three principal categories of ostomy, each defined by which part of the gastrointestinal or urinary tract has been diverted to the abdominal surface.
Colostomy
A colostomy is formed when a portion of the large bowel (colon or rectum) is brought through the abdominal wall to create a stoma. It is one of the most commonly performed ostomy procedures.
Common reasons for formation include:
- Colorectal cancer
- Diverticular disease or perforation
- Trauma or injury to the colon
- Hirschsprung’s disease (particularly in children)
- Obstruction or volvulus
Because the large bowel’s primary role is to absorb water and consolidate waste, the output from a colostomy is typically more solid or semi-formed in consistency. The exact consistency depends on where in the colon the stoma is sited: a sigmoid colostomy (near the end of the colon) tends to produce the most formed output, whilst a transverse colostomy produces softer, more variable stool.
Colostomies may be temporary — for example, to allow a section of bowel to heal after surgery — or permanent, most commonly when the rectum and anus must be surgically removed (as in an abdominoperineal resection for rectal cancer).
Loop vs End Colostomy
A loop colostomy involves bringing a loop of bowel to the surface and creating two openings (a proximal and a distal limb) through one stoma site. It is frequently temporary. An end colostomy involves dividing the bowel and bringing the proximal end to the surface; the distal end is either removed or closed off inside the abdomen (known as a Hartmann’s procedure).
Ileostomy
An ileostomy is formed from the ileum — the final section of the small intestine — and is brought to the surface of the abdomen, usually on the lower right side.
Common reasons for formation include:
- Crohn’s disease
- Ulcerative colitis (often following a total colectomy)
- Familial adenomatous polyposis (FAP)
- Colorectal cancer requiring removal of the large bowel
- Bowel obstruction
Because the small bowel has not completed the water-reabsorption process, ileostomy output is typically liquid to porridge-like in consistency and is produced more continuously throughout the day. Output volumes can be significant — typically 500–1,000 ml per day — making hydration and electrolyte balance an important ongoing consideration.
Loop vs End Ileostomy
As with colostomies, ileostomies may be fashioned as a loop (two openings; often temporary, used to protect a downstream bowel anastomosis) or an end ileostomy (one opening; often permanent, following removal of the entire colon and rectum).
Continent Ileostomy (Kock Pouch)
A less commonly performed variation, the continent ileostomy (or Kock pouch), involves creating an internal reservoir from the small bowel with a valve that the person drains several times a day using a catheter. It does not require an external pouching appliance. This procedure is now rarely offered due to the technical complexity and high revision rate, but remains an option at specialist centres for carefully selected patients.
Urostomy
A urostomy (also called an ileal conduit in its most common form) diverts urine away from a diseased or surgically removed bladder. A short segment of the ileum is used as a conduit: the ureters are attached to one end of the ileal segment, and the other end is brought to the abdominal surface to form a stoma. Urine drains continuously.
Common reasons for formation include:
- Bladder cancer requiring cystectomy
- Spinal cord injury or neurogenic bladder
- Pelvic trauma
- Bladder exstrophy (a congenital condition)
- Radiation damage to the bladder
Urostomy output is continuous liquid urine, so the pouching system used differs from bowel ostomy appliances — urostomy pouches incorporate a drainage tap to allow emptying throughout the day and overnight bags for nocturnal use.
Temporary vs Permanent Ostomies
All three main ostomy types can be either temporary or permanent:
- A temporary ostomy is created to allow downstream bowel to heal, reduce inflammation, or manage an acute emergency. Reversal surgery is planned once the person has recovered.
- A permanent ostomy is necessary when the relevant organ (bladder, rectum, or a large section of bowel) has been removed or is irreparably damaged.
The distinction matters for psychological adjustment as well as practical planning. Research suggests that people facing a permanent ostomy benefit from pre-operative counselling and early input from a specialist stoma care nurse.
Siting and Pouching Systems
Regardless of type, the position of the stoma on the abdomen is carefully planned before surgery — ideally by a stoma care nurse — to avoid skin creases, bony prominences, and waistbands, all of which complicate appliance wear. The pouching system (appliance) used will differ between bowel and urinary ostomies in terms of design, though the principles of creating a secure, leak-free seal around the stoma remain consistent.
The Bottom Line
The three main types of ostomy — colostomy, ileostomy, and urostomy — each reflect a different part of the body being diverted, and each carries its own characteristics in terms of output, care routine, and lifestyle considerations. Whilst the prospect of living with a stoma can feel daunting, the majority of people adapt well and maintain full, active lives. Every person’s situation is individual, and the guidance of a qualified stoma care nurse (also known as an enterostomal therapy nurse) is invaluable — both in the early post-operative period and on an ongoing basis. Always consult your stoma care nurse or treating clinician for advice tailored to your specific type of ostomy and circumstances.
Common questions
Frequently asked questions
- What is the difference between a colostomy and an ileostomy?
- A colostomy is formed from the large bowel (colon), whilst an ileostomy is formed from the small bowel (ileum). Because the small bowel has not yet absorbed as much water, ileostomy output tends to be more liquid and higher in volume than colostomy output, which is often more formed. Both types can be temporary or permanent depending on the underlying condition and surgical plan.
- Can an ostomy be reversed?
- Many ostomies, particularly those created as a temporary measure during bowel surgery or after trauma, can be reversed once the underlying bowel has healed. Whether reversal is possible depends on how much bowel remains, the nature of the original condition, and the person's overall health. A colorectal surgeon and stoma care nurse will assess suitability for reversal on an individual basis.
- Will I be able to eat normally with an ostomy?
- Most people with an ostomy can return to a varied and enjoyable diet, though some adjustments may be needed, particularly in the early weeks after surgery. People with an ileostomy are advised to chew food well and stay well-hydrated, as certain high-fibre foods can cause blockages. A stoma care nurse or dietitian can provide personalised dietary guidance.
- Is a urostomy the same as a catheter?
- No — a urostomy is a surgically created opening through which urine drains continuously from the body via a stoma on the abdomen, collected in a pouching system. A catheter is a tube inserted through the urethra or directly into the bladder. They serve similar goals in certain situations but are anatomically and functionally distinct procedures.
- How do I know which type of ostomy I have?
- Your surgical team will explain your specific procedure before and after surgery, and this information will be recorded in your medical notes. Your stoma care nurse is the best person to clarify the type of ostomy you have, where it is located, and what care routine is appropriate for you.
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