A diverting loop ileostomy is a temporary surgical opening in your abdomen that reroutes stool away from your colon, allowing a surgical connection further downstream to heal without being exposed to waste. It’s one of the most common types of ostomy, and it’s almost always designed to be reversed once healing is complete, typically within 3 to 6 months.
How the Procedure Works
During surgery, the surgeon pulls a loop of the ileum (the last section of your small intestine) through a small opening in your abdominal wall and partially opens it on the skin’s surface. This creates a small, round piece of exposed intestinal tissue called a stoma, usually about the size of a quarter to a half-dollar. The stoma has two openings side by side. The upstream opening (called the proximal limb) is the one that passes stool into an external pouching system you wear on your skin. The downstream opening (the distal limb) leads toward your colon and mainly drains small amounts of mucus that the intestinal lining naturally produces.
Because the stool exits your body before it ever reaches your colon or rectum, any surgical repair in those areas gets a chance to heal in a clean, low-pressure environment. That’s what “diverting” means: the waste stream is diverted away from the healing site.
Why Surgeons Use It
The most common reason for a diverting loop ileostomy is to protect a new surgical connection (anastomosis) in the lower colon or rectum. When surgeons remove a section of bowel, often for colorectal cancer, they stitch or staple the remaining ends back together. If that connection is low in the pelvis, roughly 5 to 6 centimeters or less from the anal opening, the risk of a leak is high enough that diverting stool away from the site significantly improves outcomes.
Other situations where a diverting loop ileostomy is used include:
- Ileal pouch-anal anastomosis (J-pouch surgery) for ulcerative colitis, where the new internal pouch needs time to heal before it starts handling stool
- Severe perianal Crohn’s disease, where diverting stool allows inflamed tissue around the anus to recover
- Diverticular perforation, where a primary repair is made but needs protection
- Obstructing colorectal cancer, as a bridge procedure before the tumor can be surgically removed
Surgeons generally prefer a loop ileostomy over a loop colostomy for diversion because it tends to be easier to reverse and has a lower complication profile.
Loop Ileostomy vs. End Ileostomy
The key difference is permanence. A loop ileostomy preserves the connection between the small intestine and the colon. The intestine is brought to the surface as a loop, not cut in two, which makes reconnecting it later a relatively straightforward operation. An end ileostomy, by contrast, involves bringing the cut end of the small intestine to the surface with nothing remaining downstream. This is typically done when the entire colon has been permanently removed, meaning the patient will manage a stoma for life.
If you’ve been told you’re getting a diverting loop ileostomy, the plan is almost certainly temporary.
What to Expect From Stoma Output
Because waste exits from the small intestine rather than the colon, it hasn’t gone through the water-absorbing process that normally happens in the large bowel. The output is liquid to pasty, similar in consistency to a thick soup or oatmeal. You’ll empty or change your pouching system several times a day.
A normal daily output volume varies, but output exceeding 1,000 to 2,000 milliliters per day for several consecutive days is considered “high output” and happens in roughly 16% of patients. High output leads to dehydration and electrolyte imbalances, particularly low magnesium and sodium. Signs to watch for include weight loss, dry mouth, increased thirst, reduced urination, and lightheadedness.
Daily Stoma Care
Managing a pouching system involves a learning curve, but most people develop a routine within a few weeks. The basic process involves cleaning the skin around the stoma with water (no soap needed), measuring the stoma to ensure the appliance fits snugly without squeezing it, and pressing the new pouch into place. A well-fitting appliance is critical because the biggest skin-related complication, peristomal dermatitis, happens when the watery, alkaline output leaks under the seal and contacts skin. This output contains digestive enzymes that break down skin quickly, causing painful irritation and ulceration.
Barrier rings, skin-protective powders, and paste strips help create a better seal. A stoma that protrudes about 2 to 3 centimeters from the skin surface drains most cleanly into the pouch and minimizes leaks. If your stoma sits flush or retracts, a convex pouching system can help direct output into the bag rather than under the seal.
Diet and Hydration
Staying hydrated is the single most important daily task with an ileostomy. You should aim for about 8 to 10 glasses (roughly 2 liters) of fluid per day. Plain water alone isn’t enough because you’re losing sodium and potassium through your stoma output. Sports drinks, oral rehydration solutions like Pedialyte, broth, and tomato juice help replace those electrolytes more effectively.
Foods high in potassium (bananas, orange juice without pulp, potatoes without skin, broccoli, yogurt) and foods high in sodium (crackers, cheese, broth, soy sauce) should become regular parts of your diet.
For the first 3 to 4 weeks after surgery, certain foods carry a risk of causing a blockage at the stoma. These are generally high-fiber, stringy, or hard-to-digest items: raw vegetables like celery and cabbage, corn, popcorn, nuts and seeds, dried fruits, mushrooms, raw fruit with skin (apples, grapes, blueberries, strawberries), and whole grains. After the initial recovery period, many people can reintroduce these foods gradually by chewing thoroughly and eating small amounts at a time.
Common Complications
Peristomal dermatitis is the most frequent issue. The digestive enzymes in ileostomy output are aggressive, and even brief skin contact causes redness, burning, and breakdown. Keeping a properly fitting appliance and using skin barriers are the primary defenses.
High-output stoma is the second major concern. Risk factors include shorter remaining bowel length, diabetes, certain medications, infections like C. difficile, and abdominal infections. Treatment involves replacing fluids and electrolytes and using medications that slow intestinal movement. If you notice your pouch filling much faster than usual or you develop signs of dehydration, that warrants prompt attention.
Physical Activity
Clear, universal guidelines for exercise with a stoma don’t yet exist, but most people can return to a wide range of physical activities once they’ve healed from surgery and found a pouching system that stays secure during movement. Finding the right appliance is often described as the key factor in regaining confidence to be active. Even demanding activities, including marathon running, are possible, though people with ileostomies lose more sodium through their stoma output during exercise and benefit from electrolyte drinks at any temperature, not just in heat.
Reversal Timeline and Rates
Reversal is generally performed 3 to 6 months after the original surgery, once imaging or an exam confirms the downstream connection has healed properly. If you need chemotherapy after your initial operation, that can push the timeline further out. Chemotherapy was the most common reason for delayed reversal in one study, accounting for about 35% of delays.
About 75% of patients with a diverting loop ileostomy go on to have it successfully reversed. The remaining 25% may keep their stoma due to advanced cancer, medical conditions that make another surgery risky, complications at the original surgical site, or in some cases personal choice. Reversal is a smaller operation than the original surgery, and most people resume normal bowel function afterward, though it can take weeks for bowel habits to fully settle.