A colostomy is a surgical opening in the abdomen that allows stool to leave the body through a section of the large intestine (colon) rather than through the rectum. During the procedure, a surgeon brings part of the colon through the abdominal wall to create a small, round opening called a stoma. Stool passes through the stoma into an external pouch worn against the skin. Some colostomies are temporary, designed to let damaged or healing tissue recover, while others are permanent.
Why a Colostomy Is Needed
A colostomy becomes necessary when stool can no longer safely pass through the lower part of the colon or rectum. The most common reasons include colorectal cancer, diverticulitis (infected pouches in the colon wall), and inflammatory bowel disease such as Crohn’s disease or ulcerative colitis. Traumatic injuries to the colon, like those from accidents or gunshot wounds, can also require one.
In some cases, the surgery is done specifically to protect a fresh surgical connection further down the colon, giving it time to heal without stool passing over it. Bowel obstructions caused by tumors, scar tissue, or other conditions are another common trigger. Less frequently, nerve damage affecting the rectum or anus, anal cancer, rectal cancer, or congenital conditions like Hirschsprung’s disease in children may lead to a colostomy.
Types Based on Location
The type of colostomy you have depends on which section of the colon is brought to the surface, and this directly affects what your output looks like.
An ascending colostomy uses the first section of the colon, on the right side of the abdomen. Because stool has spent very little time in the large intestine at this point, bowel movements are loose, pasty, or watery. A descending colostomy uses the colon further along, on the left side, producing soft stool. A sigmoid colostomy, the most common type, uses the very last portion of the colon before the rectum. Output from a sigmoid colostomy is soft to firm and closest to what a normal bowel movement looks like.
The consistency matters because it affects which pouching system works best and whether techniques like irrigation (discussed below) are an option.
End Colostomy vs. Loop Colostomy
Beyond location, colostomies also differ in how the surgery itself is performed.
In an end colostomy, the surgeon divides the colon and brings the upper end to the surface as the stoma. The remaining lower portion is either sealed shut and left inside the abdomen or removed entirely. End colostomies are often created after part of the colon has been removed due to cancer, trauma, or diverticulitis, and they are more likely to be permanent.
A loop colostomy pulls an intact loop of colon to the surface without fully dividing it. Both the upstream and downstream openings share a single stoma site. Loop colostomies are typically temporary. When it comes time to reverse the surgery, closing a loop colostomy involves a shorter hospital stay, less blood loss, and a lower complication rate compared to reversing an end colostomy.
Temporary vs. Permanent
Many colostomies are planned as temporary from the start. They are commonly used to manage diverticulitis, colorectal cancer recovery, and inflammatory bowel disease, where the goal is to divert stool away from a healing surgical site and reduce the risk of dangerous leaks.
Reversal surgery generally happens no sooner than 60 to 90 days after the original procedure. This window gives the body time to recover from the first surgery and allows internal inflammation and swelling to settle. For colostomies created during a Hartmann’s procedure (a common operation for perforated diverticulitis), some surgeons recommend waiting three to six months before attempting reversal.
Not every temporary colostomy gets reversed. Complications from the original surgery, the need for chemotherapy, advanced age, or other health conditions can make reversal too risky. Research shows that only about half of patients who undergo a Hartmann’s procedure ever have their colostomy reversed.
Recovery After Surgery
Full recovery from a colostomy takes roughly eight weeks before most people return to their usual activities. During that time, you’ll learn to care for your stoma and manage the pouching system, typically with guidance from a specialized nurse called a wound, ostomy, and continence (WOC) nurse.
In the first few weeks, your diet plays an important role. Eating six small meals a day instead of three large ones, chewing thoroughly, and sticking to bland, low-fiber foods helps your colon heal. Foods to limit early on include raw vegetables (except lettuce), raw fruits with skin like apples and grapes, whole grains, dried beans, fried or high-fat foods, and carbonated drinks. You should aim for about eight to ten glasses of water a day to stay hydrated. New foods get added back one at a time so you can identify anything that causes gas, odor, or discomfort.
The Pouching System
Stool collects in a pouch (sometimes called a bag or appliance) that adheres to the skin around the stoma using a flat adhesive wafer. The pouch is discreet under clothing and can be emptied or changed as needed.
A flat wafer works well when the skin around the stoma is smooth and the stoma itself protrudes slightly above the skin surface. If the area around the stoma dips inward, has creases or folds, or if the stoma sits level with or below the skin, a convex wafer is often a better choice. Convex wafers press gently into the peristomal skin to help the stoma protrude and create a better seal, which prevents leakage and the skin irritation that comes with it.
Irrigation as an Alternative
Some people with a descending or sigmoid colostomy can use a technique called colostomy irrigation to regulate their bowel movements. It works similarly to an enema: water is introduced through the stoma to stimulate the colon to empty on a schedule. Done consistently, irrigation can allow you to go without wearing a full collection pouch between sessions, using only a small cap or patch over the stoma instead.
Irrigation is only practical when stool is relatively firm, which is why it is limited to descending and sigmoid colostomies. It is not suitable for ascending colostomies, where output is too liquid.
Common Complications
The most frequent long-term complication is a parastomal hernia, where abdominal tissue bulges through the muscle around the stoma. Studies report hernia rates as high as 44% over time, making it something to watch for rather than a rare event. Symptoms include a visible bulge near the stoma, difficulty keeping the pouch sealed, and occasional discomfort.
Skin irritation around the stoma is another common issue, often triggered by leakage from the pouching system. When stool contacts the surrounding skin repeatedly, it can cause redness, soreness, and breakdown. A properly fitted wafer and regular skin care significantly reduce this risk. Stoma prolapse, where the stoma extends further out of the abdomen than intended, and stoma retraction, where it pulls back below the skin surface, are less common but may require adjustments to the pouching system or, in some cases, surgical correction.