A loop colostomy is a surgical procedure where a surgeon pulls a loop of the colon through an opening in the abdominal wall, partially cuts it open, and creates a stoma with two connected openings. It is the most common type of colostomy performed, and it’s usually temporary. Unlike other colostomy types that fully sever the bowel, a loop colostomy keeps both ends of the colon attached to each other, which makes it easier to reverse later.
How a Loop Colostomy Works
During the procedure, the surgeon makes an opening in your abdominal wall, pulls a section of colon through it, and cuts partway through the loop. This creates two openings side by side within a single stoma. The upper opening (called the proximal end) is still connected to your small intestine and digestive tract, so this is where stool exits your body into a collection bag. The lower opening (the distal end) connects to the remaining portion of your colon and rectum. It produces small amounts of mucus, which is normal.
To keep the loop of bowel from slipping back inside the abdomen during the first days of healing, surgeons place a small support rod or bridge underneath it. These rods are typically made of plastic or glass and stay in place for about 7 to 10 days before being removed.
The procedure can be done through open surgery or laparoscopically. Both approaches are common, with studies showing a roughly even split between the two techniques.
Loop Colostomy vs. End Colostomy
The key difference comes down to construction and intent. In an end colostomy, the colon is completely divided and the cut end is brought through the abdominal wall, folded back like a cuff, and stitched to the skin. The other end is either removed or sealed off inside the abdomen. Most permanent colostomies are end colostomies.
A loop colostomy, by contrast, keeps both sides of the bowel connected. The colon is opened on one side rather than severed entirely. Because the bowel is still in continuity, reversing it is a simpler operation: the surgeon detaches the stoma from the abdominal wall, closes the opening in the colon, and returns it to the abdomen so stool flows through normally again. This structural difference is why loop colostomies are the preferred choice when the diversion is expected to be temporary.
Why a Loop Colostomy Is Performed
The two main purposes are diversion and decompression. Diversion means routing stool away from a section of bowel that needs to heal or that has been injured. Decompression means relieving a blockage in the colon so pressure doesn’t build up dangerously.
The most common reason for a loop colostomy is abdominal trauma, particularly penetrating injuries like stab or gunshot wounds. In one study, penetrating abdominal injuries accounted for about 43% of loop colostomies. Colorectal cancer was the next most common reason at 20%, followed by perineal injuries and accidental bowel damage during other surgeries.
Loop colostomies are also used to protect surgical connections further down in the colon or rectum. After a surgeon reconnects two ends of the bowel (an anastomosis), a temporary loop colostomy diverts stool away from that connection while it heals. This reduces the risk of the connection leaking, which can cause serious infection.
What to Expect With Output and Diet
Because a loop colostomy is placed on the colon (rather than the small intestine), the stool that comes out has already had most of its water absorbed. Output tends to be semi-formed to formed, which makes it easier to manage than the watery output typical of an ileostomy.
Right after surgery, most people start with a low-residue, high-protein diet and transition to regular foods as the bowel adjusts. Small meals every 3 to 4 hours work better than large ones. Drinking 6 to 8 cups of water daily is generally recommended, and it helps to sip fluids between meals rather than drinking large amounts with food. Sugary beverages can increase output volume and are best limited.
Around 6 to 8 weeks after surgery, fiber-containing foods can be gradually reintroduced. It’s best to add new foods one at a time so you can identify anything that causes gas, odor, or changes in output consistency. A daily multivitamin is often recommended until you’re tolerating a full, varied diet.
Common Complications
Loop colostomies carry a notably higher risk of stoma prolapse compared to end colostomies. Prolapse happens when the bowel telescopes outward through the stoma, creating a visible protrusion. Transverse loop colostomies have a prolapse rate of around 30%, and the distal limb (the non-functioning side) is the segment most likely to prolapse. Loop colostomies prolapse far more often than loop ileostomies, where the rate is under 2%.
Parastomal hernia, where tissue bulges through the abdominal wall around the stoma, is another concern. Overall, parastomal hernias are estimated to affect more than 50% of stoma patients over the long term, though colostomies carry higher rates than ileostomies. End colostomies develop parastomal hernias more frequently than loop colostomies. About 7.7% of patients after colorectal cancer surgery develop a hernia severe enough to cause symptoms or require additional surgery within five years.
Skin irritation around the stoma is common with loop colostomies. Studies report peristomal skin complications in roughly 32% of loop colostomy patients. The causes range from prolonged contact with stool or moisture, mechanical friction from the pouching system, and fungal or bacterial infections. People with obesity or diabetes face a higher risk. Learning proper skin care and pouch fitting from a trained stoma nurse significantly reduces these problems.
Reversal: Timeline and Process
Most loop colostomies are reversed once the underlying condition has healed. Surgeons generally wait at least 60 to 90 days before reversal, and some evidence suggests that closing the stoma before the 90-day mark produces the best outcomes, even in patients undergoing chemotherapy.
Before scheduling reversal, your surgical team will confirm that the downstream bowel has healed properly. This typically involves a contrast enema (an imaging study where dye is introduced into the colon), a physical exam, and an endoscopic look at the surgical connection inside. If there’s a persistent leak, cavity, or stricture at the original surgical site, reversal may need to be delayed.
The reversal itself is a less extensive procedure than the original surgery. The stoma is detached from the abdominal wall, the opening in the colon is closed with sutures, and the bowel is returned to the abdomen. Because the two ends were never fully separated, reconnection is straightforward. Recovery after reversal is generally shorter than after the initial colostomy creation, though it still takes several weeks for bowel habits to normalize.