A parastomal hernia is a bulge that forms around a stoma, the surgically created opening in the abdomen used for waste collection after bowel or bladder surgery. It happens when abdominal contents, usually a loop of intestine or fatty tissue called the omentum, push through the weakened muscle wall right next to the stoma site. It’s one of the most common complications after stoma surgery, affecting roughly 1 in 5 patients within two years and more than 1 in 3 within five years.
How a Parastomal Hernia Develops
Creating a stoma requires cutting a hole through the layers of abdominal muscle. That opening never fully regains its original strength, and over time the gap can widen. When it does, the contents of the abdomen press outward through the defect, forming a sac beneath the skin. The result is a noticeable bulge around the stoma that may be soft and reducible (meaning you can gently push it back in while lying down) or firm and fixed.
This is technically a type of incisional hernia, since it occurs at the site of a surgical incision. But because of the unique challenges of managing a stoma appliance over the bulge, parastomal hernias come with their own set of problems and treatment considerations.
Who Is Most at Risk
Carrying extra weight is the single strongest predictor. A BMI above 25 raises the risk, and a large study of over 6,300 patients with permanent stomas found that a BMI above 30 was the only independent risk factor in their analysis. The size of the surgical opening matters too: when the hole cut through the abdominal wall exceeds about 34 millimeters, the risk climbs significantly. In fact, every additional millimeter of stoma diameter increases the likelihood of hernia formation by about 10%.
Other factors that contribute include older age, emergency surgery (which doesn’t allow for careful placement), and conditions that increase abdominal pressure over time, such as chronic coughing or heavy lifting. The type of stoma also plays a role: colostomies (from the large intestine) tend to develop hernias more often than ileostomies (from the small intestine), partly because the opening required is larger.
What It Looks and Feels Like
The most obvious sign is a bulge or swelling around the stoma. It often appears gradually over months or years, though some people notice it within weeks of surgery. The bulge typically gets larger when you stand up, cough, or strain, and may flatten when you lie down. Many people first notice it because their stoma appliance stops fitting properly, leading to leaks and skin irritation.
Some parastomal hernias cause no discomfort at all. Others bring a dragging sensation, aching around the stoma, or difficulty with appliance management. Larger hernias can change the shape and direction of the stoma itself, making output harder to manage. In rare but serious cases, a loop of bowel can become trapped in the hernia (incarceration) or lose its blood supply (strangulation). Sudden severe pain, nausea, vomiting, or the stoma turning dark in color are signs that need emergency attention.
How Parastomal Hernias Are Sized and Classified
Doctors categorize these hernias based on two factors: the size of the defect and whether there’s also an incisional hernia elsewhere along the surgical scar. A defect of 5 centimeters or smaller is considered small, while anything larger is classified as large. The European Hernia Society uses four types:
- Type I: Small hernia (5 cm or under), no other incisional hernia
- Type II: Small hernia with an additional incisional hernia nearby
- Type III: Large hernia (over 5 cm), no other incisional hernia
- Type IV: Large hernia with an additional incisional hernia
Each type is also noted as either primary (first occurrence) or recurrent (returning after a previous repair). This classification helps surgeons decide on the best approach to treatment.
Living With It: Non-Surgical Management
Many parastomal hernias, especially smaller ones that don’t cause significant symptoms, are managed without surgery. The main tool is a support garment, essentially a firm elastic belt or binder worn around the abdomen. These garments apply gentle pressure over the hernia to keep it from bulging outward, which can improve appliance fit and reduce discomfort during activity.
There’s surprisingly little formal research on how well these garments work. A review by the Canadian health technology agency found no studies that directly measured their effectiveness compared to no treatment. Despite that evidence gap, clinical guidelines from nursing and surgical organizations consistently recommend them, particularly when fitted by a stoma care nurse who can account for your body shape, activity level, and preferences. Getting the right fit matters: a poorly fitting support belt can make appliance problems worse rather than better.
Practical lifestyle adjustments also help manage the hernia day to day. Avoiding heavy lifting, supporting your abdomen when coughing or sneezing, and maintaining a healthy weight can all slow the hernia’s progression. A stoma care nurse can also help you adapt your appliance system to accommodate the changed shape around your stoma.
When Surgery Is Considered
Surgery becomes an option when the hernia causes persistent pain, frequent appliance leaks that damage the skin, or complications like bowel obstruction. Not every parastomal hernia needs repair. Because recurrence rates after surgery are significant, many surgeons recommend living with a manageable hernia rather than operating on one that isn’t causing major problems.
The two most common surgical techniques both use mesh to reinforce the abdominal wall. In the keyhole approach, the mesh has a hole cut in its center for the bowel to pass through. In the Sugarbaker approach, the mesh covers the entire defect and the bowel is rerouted to pass underneath it along the abdominal wall. A third option, the sandwich technique, combines elements of both.
Overall recurrence rates after laparoscopic repair run about 17%, but the numbers vary by technique. The Sugarbaker method has historically shown a recurrence rate around 10%, compared to roughly 28% for the keyhole approach. A meta-analysis of 593 repairs found that Sugarbaker repairs were significantly less likely to recur, though more recent studies from 2015 onward suggest the gap between techniques may be narrowing as surgical methods improve. The sandwich technique has shown promising early results, with only 1 recurrence out of 47 repairs in one pooled analysis, but the data is still limited.
Another option is relocating the stoma to a different part of the abdomen entirely, though this creates a new surgical site that carries its own risk of hernia formation down the line.
Preventing a Parastomal Hernia
One of the most significant advances in prevention is placing a piece of mesh at the time of the original stoma surgery, before any hernia develops. A large meta-analysis found that this prophylactic mesh reduced hernia formation by more than half over follow-up periods beyond six months. The benefit held up across both randomized trials and observational studies, and applied to both bowel and urinary stomas. Placing the mesh in the retromuscular position (between layers of the abdominal wall rather than directly against the bowel) was the most effective approach.
Not all surgeons use prophylactic mesh routinely, but the evidence supporting it has grown strong enough that it’s increasingly recommended, especially for patients at higher risk due to obesity or the need for a large stoma opening. If you’re facing stoma surgery, it’s worth asking your surgeon whether preventive mesh placement is appropriate for your situation.
The Long-Term Picture
Parastomal hernias tend to develop within the first few years after stoma creation. Research tracking patients over time found that the cumulative rate climbed steadily, from about 11% at one year to 38% at five years, but then plateaued. No new hernias developed after the five-year mark in that study, which suggests that if your abdominal wall holds for the first several years, it’s likely to remain stable.
For those who do develop a hernia, the majority manage it successfully without surgery. The hernia may grow slowly over time, and periodic reassessment with a stoma care nurse helps ensure your support garments and appliance system keep up with any changes. Surgery remains a reliable option for hernias that become too large or symptomatic to manage conservatively, even if the possibility of recurrence means the decision is rarely straightforward.