An ostomy bag is a small, flexible pouch that collects bodily waste from a surgically created opening in the abdomen called a stoma. Between 725,000 and 1 million people in the United States currently live with an ostomy. The surgery reroutes part of the intestine or urinary tract so that waste exits through the abdominal wall instead of following its normal path, and the bag attaches to the skin around that opening to catch everything that comes out.
Why Someone Might Need an Ostomy
An ostomy becomes necessary when disease, injury, or a birth defect prevents waste from leaving the body the usual way. The most common reasons include colorectal cancer, inflammatory bowel disease (Crohn’s disease and ulcerative colitis), diverticular disease, intestinal obstruction, bladder cancer, and chronic incontinence. Some ostomies are temporary, giving a damaged section of the bowel time to heal before being reconnected. Others are permanent when the affected portion of the intestine or bladder has been removed entirely.
Three Main Types of Ostomies
The type of ostomy depends on which organ is being rerouted and where along the digestive or urinary tract the surgeon creates the opening.
Colostomy
A colostomy brings a section of the large intestine (colon) through the abdominal wall, typically on the lower left side. The consistency of output depends on which part of the colon is used. A sigmoid colostomy, made from the last portion of the colon, produces soft to firm stool that most closely resembles a normal bowel movement. An ascending colostomy, made higher up, produces loose, pasty, or watery output because less water has been absorbed from the waste.
Ileostomy
An ileostomy uses the lowest part of the small intestine and is usually positioned on the right side of the abdomen. Because food hasn’t passed through the colon yet, the output is consistently liquid or pasty. There’s no voluntary control over what comes out of the stoma, so the bag must be worn at all times. Gas also passes freely through the opening.
Urostomy
A urostomy redirects urine. The surgeon uses a small piece of intestine to create a channel from the ureters (the tubes connecting the kidneys to the bladder) to an opening in the abdomen. Urine flows continuously into the pouch, so the bag needs to be emptied more frequently than those used for stool.
How the Pouching System Works
An ostomy bag is actually part of a two-component system. The first component is a skin barrier, sometimes called a wafer, which is an adhesive disc that sticks to the skin surrounding the stoma and creates a seal. The second is the pouch itself, which hangs below the wafer and collects output. Together they’re often called a “pouching system.”
There are two main designs. A one-piece system combines the skin barrier and pouch into a single unit. It feels simpler since there’s nothing to snap together, but when you change the pouch, the adhesive barrier comes off too. A two-piece system keeps the skin barrier attached to your body and lets you swap just the pouch by connecting it through a coupling mechanism, often a snap-style ring. This means less adhesive removal and less irritation to the skin around the stoma.
Most pouches have a drainable opening at the bottom so you can empty them without removing the entire system. The general rule is to empty the pouch once it reaches about one-third full, which prevents it from becoming heavy enough to pull away from the skin or show under clothing.
Changing and Emptying Schedule
Right after surgery, the pouching system is typically changed every one to four days while nurses monitor healing. Once you’re home and comfortable with the routine, most people change the entire system about one to two times per week. Emptying, on the other hand, happens multiple times a day. How often depends on the type of ostomy and your diet. Ileostomies produce more liquid output and generally need emptying more frequently than colostomies.
Keeping the Skin Healthy
The skin around a stoma should look the same as skin anywhere else on the abdomen. In practice, that’s the biggest ongoing challenge for people with ostomies. The two most common problems are moisture damage and adhesive injury.
Moisture damage happens when stool or urine leaks under the skin barrier and sits against the skin. This causes redness, irritation, and eventually a breakdown of the skin’s surface. In warm, moist conditions, a fungal rash can develop, recognizable by a red center with distinct satellite spots around it. Adhesive injury occurs from repeatedly removing and reapplying the wafer, which can strip the top layer of skin or inflame hair follicles. A well-fitting pouching system that matches the size and shape of the stoma is the most effective way to prevent both problems.
Several accessories help maintain a good seal. Moldable barrier rings are soft, flexible rings that press around the base of the stoma to fill in skin folds or uneven contours, creating a flatter surface for the wafer to stick to. They’re especially useful for stomas that are recessed or irregularly shaped. Ostomy belts provide additional security by wrapping around the waist and anchoring the pouching system in place during physical activity.
Eating and Drinking After Ostomy Surgery
Diet matters more than most new ostomates expect. For the first few weeks after surgery, a bland, low-fiber diet is standard. That means cooked, easy-to-digest foods with nothing spicy, heavy, or fried. Small, frequent meals (six per day rather than three large ones) help the digestive system adjust, and thorough chewing reduces the risk of blockage at the stoma.
Hydration is critical, particularly with an ileostomy. Because the colon is bypassed, the body absorbs significantly less water from food. Drinking eight to ten glasses of fluid per day helps prevent dehydration. If diarrhea occurs, sports drinks or oral rehydration solutions replace lost electrolytes more effectively than water alone.
High-fiber foods like whole grains, raw vegetables, raw fruits with skin, and dried beans are reintroduced slowly, typically starting about two weeks after surgery and one food at a time. This approach lets you identify which foods your body tolerates well and which cause problems. Some foods are known to increase gas or odor in the pouch: asparagus, broccoli, cabbage, cauliflower, onions, garlic, eggs, fish, beer, and carbonated drinks are common culprits. They don’t need to be avoided permanently, but knowing their effects lets you plan around social situations.
Constipation, defined as fewer than three bowel movements per week or hard, difficult-to-pass stool, can also occur. Light exercise like walking, hot water with lemon, and adequate fiber intake (once cleared by a doctor) all help keep things moving.
What Modern Ostomy Bags Look Like
Today’s pouching systems are a far cry from the bulky, rigid devices of past decades. Current designs use thin, flexible materials that lie flat against the body and are nearly invisible under most clothing. Baseplates have become softer and more adaptable, with some designed to flex between convex and concave shapes depending on body contours. This is particularly useful when a stoma sits on a curved or bulging part of the abdomen, where a rigid baseplate would fail to maintain a seal.
Many pouches now include built-in charcoal filters that release gas while neutralizing odor, so the pouch doesn’t balloon up between emptyings. Moldable hydrocolloid rings that conform to irregularly shaped stomas without cutting or trimming have also become widely available, simplifying what used to be a fussy part of the routine.