A colostomy is a surgical opening, called a stoma, that connects the large intestine to the abdominal surface, providing a pathway for waste to exit the body. The waste is then collected in a pouch worn by the patient. A colostomy is used when a part of the large intestine (which plays an important role in the body's ability to process waste) is surgically removed or when the flow of stool needs to be diverted from exiting via the rectum due to partial blockage or damage to the large bowel.
The large intestine (also called the large bowel) is made up of the colon and rectum and is connected to the small intestine. The small intestine (also called the small bowel) is where nutrients—including proteins, fats, and carbohydrates—are digested and absorbed into blood vessels. Remaining food that cannot be digested moves from the small intestine to the large intestine, specifically to the colon, which absorbs water from the waste and stores the waste until the next bowel movement.
Several medical conditions affect the colon so that part or all of the five-foot-long organ is unable to function properly:
- An abdominal infection caused by a ruptured colon
- An externally caused injury to the colon or rectum
- A blockage of the large intestine
- An abnormal connection between the anus and reproductive organs
- Certain types of cancer, such as colorectal cancer 
Most patients with cancer who need a colostomy only need it temporarily—usually for several months—to help the colon or the rectum heal after a portion has been removed. However, in some cases, a permanent colostomy may be needed.
Types of colostomy
There are several types of colostomies that correspond to the four main sections of the colon.
Ascending colostomy. An ascending colostomy is located in the ascending colon, which extends from the beginning of the large intestine to the right side of the abdomen. In this procedure, only part of the colon remains functional. As a result, little water is absorbed from the waste, and the discharge is usually liquid. However, this type of procedure is rare because an ileostomy (a procedure in which the small intestine is diverted to the abdominal wall and waste is emptied into a pouch) is more appropriate for cases involving the ascending colon.
Transverse colostomy. A transverse colostomy is located in the transverse colon, which crosses the top of the abdomen. Transverse stool is usually soft or loose because only a small portion of the colon has absorbed water from the indigestible material. This is a common type of colostomy, and there are three versions of it. For patients with a loop colostomy, the colostomy stoma has one opening, and stool can exit through that opening. In this case, the colon is not disconnected, and patients will sometimes pass stool or gas through the rectum. For patients with a single-barrel colostomy, the colon—including the rectum and anal opening—is removed below the colostomy. This type of colostomy is permanent. For patients with a double-barrel colostomy, the colon is divided, and the two ends form two separate stomas. Stool exits from one of the stomas, while mucus made by the colon exits from the other. This type of colostomy is not performed as often as the other two types.
Descending colostomy. A descending colostomy is located in the descending colon, which takes waste down the left side of the abdomen. The stool there is usually firm because it has moved across functioning portions of the colon.
Sigmoid colostomy. A sigmoid colostomy—the most common type—is located in the sigmoid colon, the bottom portion of the large intestine, which moves waste to the rectum. Sigmoid colostomies produce stool that is more solid and regular than other colostomies.
The surgical procedure
The surgery to create a colostomy may be done through a large surgical incision (cut) in the abdomen or through small incisions in the skin, called laparoscopic surgery . Laparoscopic surgery is a minimally invasive type of surgery that minimizes pain and post-operative recovery time. With both types of surgery, the patient is placed under general anesthesia.
The surgeon stitches one end of the colon to a stoma. A special bag is then attached to the stoma, allowing solid waste and gas from the colon to empty into it. Physicians usually place stomas on a smooth skin surface on the stomach in a location where the patient can easily see it and take care of it.
Risks associated with the surgery include bleeding inside the colon, damage to neighboring organs, infection, and stoma bleeding.
Recovery from surgery
A complete recovery after receiving a colostomy may take up to two months, with most patients needing to stay in the hospital for up to one week after the procedure. Eating is restricted during this period to help the colon heal. If the colostomy is temporary, a reversal surgery may be performed approximately 12 weeks later, after the colon has healed.
Once you have recovered from surgery, you will need to empty the colostomy bag several times per day, preferably when the bag is less than one-half full. There are several types of colostomy pouches available, including open-end (drainable) and closed-end (disposable) pouches. Some pouches have a filter that deodorizes and vents gas so that the bag does not become too stretched and come off of the abdomen or burst.
It is important to keep the skin surrounding the stoma, called peristomal skin, clean to avoid infection. The stoma will always appear red and may bleed occasionally, which is normal. However, bleeding should not continue for long periods.
Amounts of stool and gas deposited into the pouch will vary based on the type of colostomy you received and your diet. Your doctor or nurse can provide information on the types of foods that you should avoid to reduce gas.
You will not be able to control when stool and gas move into the pouch because the colon cannot voluntarily block and hold waste like the rectum does.
Living with a colostomy
Although a colostomy will alter your life, modern colostomy products are designed to minimize inconvenience and allow you to do most of the activities that you could before surgery. You should be able to wear the same type of clothes you wore before the colostomy because pouches are designed to be inconspicuous, fitting close to the body. Products also have odor-barrier film that traps bad odor, which only releases when the colostomy pouch is being emptied.
A colostomy should not restrict you from the activities of your daily life. Patients with colostomies go to work, play most sports, and engage in sexual activity. Reasonable activity will not hurt you or your stoma.
Despite efforts to adjust, some people may feel depressed or embarrassed by their colostomy. Reaching out to a support group  of patients with colostomies, either in person or online, may help answer your questions and provide emotional support. Learn more about body image and cancer .
Last Updated: March 07, 2011