A stoma is typically placed on the front of the abdomen, through the rectus abdominis muscle, and its exact position depends on the type of stoma being created. Colostomies usually sit on the left side of the abdomen, ileostomies on the right, and urostomies also on the right. But calling out a quadrant only tells part of the story, because the precise spot within that quadrant is chosen with surprising care, factoring in everything from skin folds and belt lines to whether the person will be sitting or standing when managing the pouch.
Why Location Varies by Stoma Type
The three most common types of stoma each connect to a different part of the body’s plumbing, and that anatomy dictates where on the abdomen the opening makes sense. A colostomy diverts the large intestine, and because the descending colon runs along the left side of the abdominal cavity, surgeons bring the stoma out through the left lower abdomen in most cases. A sigmoid colostomy, the most common variety, sits even lower on the left. A transverse colostomy, less common, may appear higher up, sometimes to the right of the navel, because the transverse colon crosses the upper abdomen from right to left.
An ileostomy diverts the small intestine, specifically the ileum, which lies in the right lower portion of the abdominal cavity. The stoma therefore emerges on the right side of the abdomen, generally below the navel. A urostomy, which reroutes urine after bladder removal, also appears on the right side. In the most common technique, an ileal conduit, surgeons use a short segment of the ileum to create a channel. The ureters are attached to this segment, and the opening is created on the right side of the abdomen.1Bladder Cancer Canada. Ileal Conduit (Ostomy)
In all three cases, the stoma itself is a small, round or oval opening, usually a couple of centimeters across. It protrudes slightly from the skin surface so that output drains cleanly into an external pouching system. The color is a moist pink or red, similar to the inside of your cheek, because it is exposed intestinal lining.
The Rectus Abdominis Rule
One of the most important principles in stoma placement is that the bowel should be brought out through the body of the rectus abdominis muscle rather than at its edge or through the flank. The rectus muscle is the paired vertical muscle running down the center of the abdomen on each side of the midline. Bringing the stoma through this muscle matters because the muscle acts like a natural reinforcement around the opening, helping to prevent the intestine from bulging outward over time.
A classic study comparing stoma sites found that when the bowel was brought through the rectus muscle, only about 3 percent of patients developed a parastomal hernia. When the stoma was placed lateral to the rectus, that number jumped to roughly 22 percent.2British Journal of Surgery. Parastomal hernia in relation to site of the abdominal stoma That sevenfold difference made through-the-rectus placement the standard teaching in colorectal surgery. Parastomal hernias are among the most common long-term stoma complications, and once they develop, they can make pouching difficult, cause discomfort, and sometimes require further surgery.
The picture is not quite as clean-cut as that classic study suggests, however. A more recent randomized trial comparing lateral pararectus placement with transrectus placement for temporary loop ileostomies found no significant difference in parastomal hernia rates between the two groups.3Colorectal Disease. A pilot single-centre randomized trial assessing the safety and efficacy of lateral pararectus abdominis compared with transrectus abdominis muscle stoma placement in patients with temporary loop ileostomies: the PATRASTOM trial That trial was small, and the stomas were temporary, so most surgeons still favor the rectus route for permanent stomas. But it hints that the relationship between muscle location and hernia risk may be more nuanced than a single rule can capture.
How the Exact Spot Gets Chosen Before Surgery
In planned (elective) surgery, the specific point on the abdomen is chosen before the patient enters the operating room. This process, called preoperative stoma site marking, typically involves a wound and ostomy care nurse who evaluates the patient’s abdomen in three positions: lying flat, sitting, and standing. The nurse looks for a stable, flat area of skin that stays smooth across all three postures, avoids bony prominences like the hip bone, steers clear of existing scars and skin creases, and sits within the patient’s line of sight so the person can actually see and manage the pouch.4PubMed. Does preoperative stoma marking and education by the enterostomal therapist affect outcome?
The belt line gets specific attention. A stoma placed right at the waistband of trousers or a skirt can be rubbed, compressed, and irritated throughout the day, making pouch adherence unreliable and daily life uncomfortable. Ideally the site sits below the belt line but above the groin crease, within the infraumbilical region of the chosen side. For people with larger abdomens, folds of tissue can shift substantially between positions, and the marking process accounts for that by checking which skin surface stays accessible when the person bends forward or sits in a chair.
The evidence for doing this marking is strong. A systematic review and meta-analysis found that patients who had preoperative stoma site marking experienced roughly half the rate of stoma-related complications compared with those whose site was chosen only during the operation.5PubMed. The effectiveness of preoperative stoma site marking on patient outcomes: A systematic review and meta-analysis The same analysis found that marking was also associated with fewer difficulties in self-care and higher health-related quality of life. A Canadian position statement, citing the volume of ostomy procedures performed nationally each year, recommends that preoperative marking should be routine for every fecal diversion.6PubMed Central. Preoperative stoma site marking for fecal diversions (ileostomy and colostomy): position statement of the Canadian Society of Colon and Rectal Surgeons and Nurses Specialized in Wound, Ostomy and Continence Canada
When There Is No Time to Plan
Emergency surgery changes the equation. When a patient needs an urgent bowel diversion because of a perforation, obstruction, or traumatic injury, there may be little or no time for a specialist nurse to assess the abdomen. The surgeon chooses the site intraoperatively, doing the best they can with the anatomy at hand. This is one reason emergency stomas tend to carry more complications. A study examining risk factors for stoma-related problems found that emergency surgery was a significant predictor of complications, alongside male sex and open surgical approach.7PubMed. Preoperative stoma site marking: a simple practice to reduce stoma-related complications
In an emergency, the stoma might end up in a skin fold, too close to a scar, or in a spot the patient cannot easily reach. These placement issues do not just affect appearance; they make the daily work of emptying and changing the pouch harder, which can lead to leakage, skin breakdown, and psychological distress. Some hospitals have tried to reduce this gap by having ostomy nurses available on call, even for overnight emergencies, so that at least a quick bedside assessment can happen before the patient goes to the operating room. The data on preoperative marking makes a compelling case for that effort.
What Happens When the Site Is “Wrong”
A poorly placed stoma is not just an inconvenience. Research comparing patients whose stoma was placed at an appropriate site versus an inappropriate one found measurable differences across multiple dimensions of quality of life. Patients with inappropriately sited stomas scored lower on physical functioning, role functioning, and sexual enjoyment. They also reported more pain, fatigue, insomnia, gastrointestinal problems, and breathing difficulties. Overall quality of life was significantly lower in the inappropriately placed group.8PubMed. Quality of life in stoma patients: appropriate and inappropriate stoma sites
A pooled analysis of cancer survivors with ostomies echoed these findings, concluding that stoma location is linked to quality of life and to how well people adjust to living with the ostomy.9PubMed Central. Stoma location and ostomy-related quality of life among cancer survivors with ostomies: A pooled analysis Additional research confirms that the simple act of marking the site beforehand correlates with higher quality-of-life scores afterward.10PubMed Central. The effect of preoperative stoma site marking on quality of life
The relationship between placement and well-being is not hard to understand intuitively. If the pouch cannot stick flat because it sits in a crease, it leaks. Leakage leads to skin irritation, odor anxiety, clothing changes, and withdrawal from social life. If the stoma is somewhere the person cannot see it without a mirror, emptying and changing the pouch becomes a two-handed puzzle in an awkward position. These practical hassles accumulate day after day into a genuine burden.
Common Complications Tied to Placement
Beyond parastomal hernia, several other complications relate at least partly to where and how the stoma was constructed. Peristomal skin problems are the most frequent issue overall. They happen when the pouching system does not fit well against the skin, allowing output to contact and irritate the surrounding area. A stoma placed in a concavity or near a fold is harder to seal, which makes skin breakdown more likely.
Retraction occurs when the stoma pulls back to or below the level of the skin surface instead of protruding. A retracted stoma is difficult to pouch because output cannot drain cleanly into the bag. Stenosis, or narrowing of the stoma opening, can obstruct output. Prolapse, where the intestine telescopes outward through the stoma more than intended, is another recognized complication. Necrosis, a loss of blood supply to the exposed bowel, can happen early after surgery if the tissue is stretched too tightly during construction. These complications span the spectrum from stoma types and techniques, but many can be minimized with proper site selection and surgical technique.11PubMed Central. Ostomy-Related Complications
Stoma Placement in Infants and Children
Pediatric patients present their own challenges. A newborn’s abdomen is small, and the standard landmarks used in adults do not translate neatly to an infant. For temporary stomas in babies, surgeons have sometimes used the umbilical site itself. A review of 47 infants and children who received a temporary colostomy or ileostomy at the umbilicus found that while complications were common, they were not related to the umbilical site specifically. The practical advantage was that the umbilical site made appliance placement easier on a tiny abdomen, and after the stoma was closed, the resulting scar looked like a normal belly button.12Journal of Pediatric Surgery. Use of the umbilical site for temporary ostomy: review of 47 cases
In older children and adolescents, the marking process resembles the adult approach but must account for growth. A site that works well for a seven-year-old may shift as the child grows taller and the abdomen changes shape. Pediatric ostomy nurses consider the child’s body habitus, activity level, and the likelihood that the stoma will be temporary versus permanent.
Challenging Bodies and Difficult Anatomy
Textbook stoma siting assumes a relatively standard abdominal wall, but real patients come with every variation imaginable. Obesity, prior surgical scars, skin conditions, spinal deformities that affect posture, and existing medical devices like feeding tubes or drains all complicate the picture. A patient who has had multiple prior abdominal surgeries may have adhesions or scar tissue in the usual location, forcing the surgeon to adapt.
In these situations, the surgeon and ostomy nurse may need to consider non-standard sites, sometimes placing the stoma higher on the abdomen or slightly off the usual quadrant. The guiding principles remain the same: get through the rectus muscle if at all possible, find a flat and visible area of skin, avoid scars and creases, and ensure the patient can reach and see the site. When that ideal cannot be met, the team has to make trade-offs, accepting a less-than-perfect location in exchange for a stoma that still functions. Thoughtful preoperative planning, even when the anatomy is challenging, helps surgeons identify the best available site and create a functional stoma.13PubMed Central. The Difficult Stoma: Challenges and Strategies
Wheelchair users illustrate a specific challenge. When someone spends most of the day seated, the abdominal wall folds differently than it does standing. A site chosen while the patient is lying on an operating table can end up buried in a deep skin fold when the person returns to their chair. This is exactly why the sitting-standing-lying assessment during preoperative marking is so valuable. For wheelchair users, the sitting position essentially becomes the primary position of reference rather than standing.
Living With the Location You Have
For someone already living with a stoma, the location is mostly fixed. Revision surgery can relocate a stoma, but it carries its own risks and is generally reserved for cases where the current site causes serious ongoing complications. Most people adapt by working with the site they have, choosing pouching systems that match the contour of their skin and using accessories like barrier rings or convex wafers to get a better seal over uneven surfaces.
Clothing adjustments are common. Many people with stomas on the lower abdomen shift to high-waisted pants or avoid tight belts that press directly on the pouch. Others find that stretchy waistbands or suspenders reduce pressure on the stoma area. Swimwear, athletic clothing, and even formal wear can all be managed, though it often takes some experimentation. Support groups and ostomy nurses are practical resources for navigating these specifics, because no two bodies and no two stoma placements are identical.
The psychological dimension of stoma location is real as well. A stoma visible above a low neckline swimsuit affects body image differently than one hidden below the waistband. Intimacy concerns are common, and research shows that sexual enjoyment scores are measurably lower when the stoma is poorly placed.8PubMed. Quality of life in stoma patients: appropriate and inappropriate stoma sites People who feel self-conscious about the location sometimes benefit from talking with other ostomates who have worked through similar concerns. The fact that placement quality can be assessed and predicted beforehand is one of the strongest arguments for making preoperative marking a universal practice.
When Two Stomas Share the Same Abdomen
Some surgical situations require more than one stoma. A patient might have both a colostomy and a mucous fistula, or an ileostomy and a separate urostomy. When two stomas share the abdominal wall, spacing becomes critical. Each stoma needs its own pouching system, and the flanges of two pouches cannot overlap without compromising the seal on both. Surgeons try to place the two openings far enough apart that standard pouching hardware fits without interference, but on a small or obese abdomen, finding two acceptable flat areas with enough clearance between them is a genuine puzzle.
In some cases, a dual-opening pouch can bridge two stomas that are close together, but this is a workaround rather than a preferred plan. The ideal remains sufficient separation so that each stoma can be managed independently. Preoperative marking is even more important in double-stoma scenarios because the constraints multiply: each site must individually satisfy the flatness, visibility, and muscle-path criteria, and the pair must work together spatially.