A stoma hernia (parastomal hernia) looks like a bulge or swelling around the stoma site, typically on one side more than the other. It develops when tissue or a loop of bowel pushes through the weakened abdominal wall where the stoma was created. The bulge may be subtle at first, barely noticeable under clothing, or it can grow large enough to be clearly visible even when dressed.
What the Bulge Looks Like
In its early stages, a parastomal hernia often appears as a slight fullness or asymmetry around the stoma. You might notice one side of the skin near the stoma looks puffier than the other, especially when you’re standing, coughing, or straining. The stoma itself may shift position slightly, sitting off-center compared to where it originally was.
As the hernia grows, the bulge becomes more pronounced. It can range from a soft, dome-shaped swelling the size of a fist to a large protrusion that changes the entire contour of your abdomen. These hernias develop gradually and increase in size over time. Some become large enough to be visible beneath clothing. The skin over the bulge usually looks normal in color, stretched smooth, and feels soft when you press on it. In many cases, the bulge shrinks or flattens when you lie down, then reappears when you stand up or bear down.
Surgeons classify parastomal hernias by size: those with a defect of 5 cm or smaller are considered small, while anything larger than 5 cm is classified as large. A 5 cm hernia is roughly the width of a tennis ball, so even a “small” one can be quite noticeable.
How It Differs From Stoma Prolapse
A parastomal hernia and a stoma prolapse can look similar at first glance, but they’re different problems. A hernia is a bulge in the skin and tissue around the stoma, caused by contents pushing through the abdominal wall beside it. The stoma itself may look relatively normal, though slightly displaced. A prolapse, by contrast, is a protrusion of the bowel through the stoma opening itself. The stoma becomes elongated, darker in color, and looks like a tube of intestine telescoping outward. It’s the stoma getting longer, not the surrounding belly getting rounder.
Sometimes both happen at once, which can make it hard to tell what you’re seeing without imaging. If you’re unsure, the key visual clue is location: hernia bulge is beside the stoma, prolapse extends from the stoma itself.
How Common Parastomal Hernias Are
Up to 50% of people with a stoma will eventually develop a parastomal hernia. The rates vary by stoma type: around 28% for end ileostomies and up to 48% for permanent colostomies. So if you have a stoma and notice a bulge forming, you’re far from alone. That said, only about 30% of people who develop a parastomal hernia will have symptoms severe enough to need surgery. Many people manage them conservatively for years.
Risk Factors That Make It More Likely
Certain factors raise your odds significantly. A BMI over 25 is one of the strongest predictors, because extra weight increases pressure inside the abdomen. One large study of over 6,300 patients with permanent stomas found that a BMI over 30 was the only independent risk factor for hernia formation in their analysis. Waist circumference matters too: measurements over 100 cm (about 39 inches) increased the risk by 75% in one study.
Other factors include being over 60, having diabetes, chronic lung disease that causes frequent coughing, and having a colostomy rather than an ileostomy. Surgical factors play a role as well. If the opening made in the abdominal wall was larger than 3 cm, or if the stoma wasn’t placed through the center of the rectus abdominis muscle (the main vertical muscle of the abdomen), hernia risk goes up. Some people also have genetic differences in their connective tissue that make the abdominal wall less resilient.
Practical Problems a Hernia Creates
Beyond appearance, a parastomal hernia changes the landscape your ostomy pouch sits on. The bulge alters the shape and contour around the stoma, which can break the seal of your pouching system. Leakages become more frequent, and repeated exposure to stoma output can cause skin irritation and damage around the site. Many people find they need to switch to different pouch systems, use convex wafers that accommodate the new contour, or wear hernia support garments to keep everything in place.
Support belts and garments are commonly used to manage the bulge. The right type depends on your stoma location, the size of the hernia, and the kind of pouch you use. These garments apply gentle compression to keep the hernia from protruding too far, which helps with both pouch adherence and comfort. There’s no standard guidance on how many hours a day to wear one, so most people adjust based on activity level and how bothersome the hernia is.
Warning Signs That Need Urgent Attention
Most parastomal hernias are manageable nuisances, not emergencies. But there are situations where the tissue that has pushed through the abdominal wall becomes trapped and can’t slide back in. This is called incarceration, and it can progress to strangulation, where the blood supply to the trapped tissue gets cut off.
Visual and physical red flags include a bulge that suddenly becomes hard and won’t flatten when you lie down, skin over the hernia turning red, purple, or dark, and the stoma changing color from its usual pink to a dusky or dark shade. Symptoms that accompany these changes include severe or worsening abdominal pain, nausea, vomiting, bloating, and a complete stop in stoma output. If the hernia has trapped part of the stomach or bowel, you may experience repeated vomiting as a primary symptom. These signs point to possible incarceration, strangulation, or bowel obstruction, all of which require emergency evaluation.
What You Can Do About It
If you spot an emerging bulge, the first step is having it assessed to confirm it’s a hernia and gauge its size. Many parastomal hernias are managed without surgery through support garments, careful pouch selection, and avoiding heavy lifting or activities that spike abdominal pressure. Stoma care nurses are particularly helpful for troubleshooting appliance fit as the hernia changes shape over time.
Surgery is reserved for hernias that cause persistent pain, repeated pouch failures, or symptoms of obstruction. Repair can involve repositioning the stoma to a new site, reinforcing the abdominal wall with mesh, or suturing the defect closed. The approach depends on the hernia’s size and whether there are additional abdominal wall weaknesses nearby. Recurrence after repair is common, which is one reason surgeons tend to recommend conservative management first when the hernia is tolerable.