A diverting loop ileostomy is a temporary surgical procedure that alters the path of the small intestine to allow the lower bowel to rest and heal. This surgery involves bringing a section of the small intestine, specifically the ileum, through an opening in the abdominal wall called a stoma. The primary purpose is to ensure that digestive waste bypasses a recently operated or diseased area of the colon or rectum. Because the procedure protects a downstream surgical connection, the ileostomy is nearly always intended to be reversed once healing is complete.
Defining the Diverting Loop Ileostomy
The defining characteristic of a diverting loop ileostomy is how the bowel is constructed into the stoma. Unlike an end ileostomy, where the cut end of the intestine is brought to the surface, a loop ileostomy is created by pulling a section of the ileum partially outside the abdomen. This loop is opened along one side and stitched to the skin, forming a single stoma that contains two distinct openings.
This structure divides the flow of contents, giving the loop ileostomy its diverting function. The opening closer to the stomach, known as the proximal limb, is the functional stoma through which stool exits into an external collection pouch. The distal opening, or efferent limb, is non-functional and allows mucus secreted by the resting bowel to drain.
Because the large intestine absorbs most of the water from digested food, the output from a loop ileostomy is naturally liquid or paste-like. This loose consistency is expected, as digestive contents exit before reaching the colon for water absorption. A supporting rod or bridge is sometimes placed underneath the loop immediately after surgery to prevent the intestine from slipping back inside the abdomen.
Primary Clinical Indications for Placement
Surgeons most commonly choose a diverting loop ileostomy to protect a new surgical connection, known as an anastomosis, in the lower gastrointestinal tract. Following major procedures, such as a low anterior resection for rectal cancer or complex surgery for inflammatory bowel disease, the reconnected bowel ends are vulnerable to leakage, a serious complication.
By diverting the flow of stool away from the anastomosis, the ileostomy allows the surgical site to heal without being contaminated or stressed by passing waste. While diversion does not prevent a leak entirely, it significantly reduces the severity of consequences, often preventing the need for emergency reoperation. High-risk patients, such as those with malnutrition, a very low anastomosis, or those undergoing radiation therapy, gain the most benefit from this protective measure.
The procedure can also be used in non-elective settings to provide immediate relief by diverting stool away from severe localized inflammation, trauma, or a large fistula. In these instances, the ileostomy allows the distressed section of the bowel to rest and recover before definitive treatment is performed. The temporary nature of the diversion remains the goal, allowing for eventual restoration of normal intestinal continuity.
Living with a Temporary Stoma
Adjusting to life with a loop ileostomy involves managing the continuous and often high output of liquid stool. Because the small intestine bypasses the colon, it is unable to absorb the usual amount of water and electrolytes, leading to a typical output of 500 to 800 milliliters per day. Output exceeding 1,500 milliliters per 24 hours is considered high-output and poses a significant risk of dehydration and electrolyte imbalance.
Patients must focus on maintaining hydration, often by using oral rehydration solutions that contain precise amounts of sodium and glucose to optimize absorption. Simply drinking plain water can be counterproductive, as it may increase output by drawing more sodium and water out of the body. Dietary modifications are also necessary, including avoiding foods that increase output, such as spicy dishes, high-sugar drinks, and certain high-fiber items.
Consuming stoma-thickening foods helps make the output more manageable. These include:
- Bananas
- Rice
- Applesauce
- Marshmallows
Separating fluid intake from mealtimes, sometimes by 15 to 20 minutes, can prevent liquid from flushing food through the small bowel too quickly. Specialized Wound, Ostomy, and Continence (WOC) nurses provide training on proper appliance care. This care is essential for preventing skin irritation around the stoma caused by caustic digestive enzymes in the output.
The Process of Ileostomy Reversal
Since the diverting loop ileostomy is primarily a temporary measure, the final step is typically the reversal, or takedown, procedure. Reversal surgery is generally scheduled between eight weeks and six months after initial placement, allowing sufficient time for the protected surgical site to fully heal. Before the reversal, imaging studies are often performed to ensure the lower bowel connection is sound and ready to function.
The reversal is a smaller operation, usually performed under general anesthesia. The surgeon makes an incision around the stoma site, detaches the two ends of the small intestine that formed the loop from the skin, and surgically reconnects them (anastomosed) inside the abdomen. The opening in the abdominal wall where the stoma was located is then closed, though the skin wound is sometimes left partially open to heal from the inside out.
Following the reversal, the body must adjust to the return of waste flow through the previously bypassed section of the bowel. Patients may experience temporary bowel dysfunction, characterized by frequent, urgent, and sometimes loose bowel movements. This adjustment period, which can last for several weeks or months, is expected as the distal bowel segments reawaken and regain function, leading to the eventual return to a more regulated bowel pattern.