What is a colostomy?

A colostomy is a surgical procedure used to divert one end or a loop of the large intestine out through the abdominal wall. An incision is made in the skin to create an opening known as an ostomy or stoma. Over this, a small pouch – known as a colostomy bag – is placed in order to collect excreted stool and other human waste.[1]

A colostomy can be permanent or temporary (around 65 percent of procedures are permanent) and is used to treat a variety of conditions that affect the colon and lower digestive tract. It is generally considered a routine procedure yet it does carry some risks.[2]

Reasons for needing a colostomy

A temporary colostomy may be necessary following surgeries to remove or repair part of the large intestine. The procedure allows waste to be diverted away from the repaired section of the colon, giving it a chance to recover and heal.

A permanent colostomy creates an artificial outlet for stool, and is necessary when the body can no longer rid itself of these substances naturally. This may be needed if the surgery involves the removal of the lowest part of the colon (the rectum) or the anal sphincter muscles.

Conditions and diseases that may make a colostomy necessary include:[3]

  • Abdominal/pelvic region cancers including colorectal cancer and more rarely anal, vaginal or cervical cancer.
  • Inflammatory bowel diseases including Crohn's disease, ulcerative colitis and, more rarely, diverticulitis.
  • Bowel obstructions or injuries
  • Bowel incontinence (in severe cases)
  • Hirschsprung’s disease (a rare disease where the bowel lacks nerve cells)

Types of colostomy

There are a variety of different type of colostomy, each corresponding to a different section of the colon.[4]

  • Sigmoid colostomy: This is the most common type of colostomy, affecting the lower portion of the colon.
  • Transverse loop colostomy: A transverse colostomy affects the top of the abdomen. A transverse loop colostomy externalises a loop of the intestine creating two openings; the proximal end – to which the pouch is fixed – and the distal end – which is inactive (no stool comes from this end).
  • Transverse single-barrel colostomy: This colostomy creates a single stoma through the abdominal wall. It is permanent and sometimes called a terminal colostomy.
  • Transverse double-barrel colostomy: For this colostomy, the two ends of the bowel are sutured together and passed through the abdominal wall.
  • Descending colostomy: A colostomy of the left-side of the colon. Having already passed through the right-side of the colon, the output is solid and controllable.
  • Ascending colostomy: A colostomy of the right-side of the colon. Output is typically liquid. This is a rare operation because a stoma of the small intestine is usually preferred.

Reversal of a temporary colostomy

Reversing a temporary colostomy is generally a routine procedure carried out when the colon has healed. This is normally between 12 weeks and a number of years after the initial procedure.[5]

Risks of a colostomy

Although considered a fairly routine surgical procedure, a colostomy still carries the chance of complications. As with any major surgical procedure, there are risks due to going under general anaesthesia and blood loss, as well as colostomy specific risks that include:

  • Skin complications, ranging from mild irritation to ulceration and infection (present in 18 to 55 percent of cases)
  • Retraction – when the stoma recedes into the skin (present in 32 to 40 percent of cases)
  • Parastomal hernia (present in 14 to 40 percent of cases)
  • Necrosis, caused by insufficient blood supply to the stoma (present in 2 to 22 percent of cases)
  • Stomal prolapse – when the stoma becomes displaced (present in 2 to 22 percent of cases)

Life after a colostomy

Immediately following a colostomy, a hospital stay of roughly two-weeks should be expected. To fully recover, however, two-months may be needed. After recovery, modern advancements in colostomy care and improvements in pouch design mean that – following a period of adaptation – most people are able to lead a relatively normal life.

This includes being able to go back to work, enjoy a regular diet and take part in physical activity.[6] Individuals who have undergone colostomy surgery should, however, be aware that their stoma and pouch do need to be looked after to keep them functioning correctly.[7] Advice on how to do this and how to change a colostomy bag will be given by doctors and nurses after the procedure has taken place.

  1. Healthline. “Colostomy.” Accessed July 4, 2017.

  2. The New York Times. “Colostomy.” Accessed July 4, 2017.

  3. NHS Choices. “Colostomy.” April 28, 2015. Accessed July 4, 2017.

  4. Cancer.Net. “Colostomy.” April, 2017. Accessed July 4, 2017.

  5. Healthtalk. “Colorectal Cancer.” August, 2016. Accessed July 4, 2017.

  6. Mayo Clinic. “Ostomy: Adapting to life after colostomy, ileostomy or urostomy.” August 21, 2014. Accessed July 5, 2017.

  7. Coloplast. “Living with a stoma.” Accessed July 5, 2017.