Loop ileostomy formation

A loop ileostomy is made by bringing a loop of the small bowel (called the ileum) up through the abdominal wall, opening it, and stitching the edges to the skin. Both ends of the loop sit at the surface, but only the upper (incoming) end carries the active output — the lower end leads to the downstream bowel.

The whole point of a loop ileostomy is to divert your bowel contents away from a fresh join further downstream. While the join is healing — typically over several months — the bowel contents are routed safely out through the stoma, so they never come into contact with the join. Once the join has fully healed, the stoma is reversed and normal bowel function returns.

It is, by design, temporary. The aim is to keep you safe through a vulnerable few months.

A loop ileostomy is typically formed at the same time as a more major operation:

• Low anterior resection for rectal cancer — the most common reason. Anastomoses low in the pelvis have a higher risk of leaking, and the consequences of a leak in this area are serious. A loop ileostomy reduces the clinical impact if a leak does occur.
• Restorative proctocolectomy with ileal pouch–anal anastomosis for ulcerative colitis, where the pouch needs time to heal before being used (see Subtotal Colectomy)
• Complex Crohn's surgery, particularly involving the rectum or perianal area (see Crohn's Perianal Disease)
• Defunctioning when bowel needs to rest — for example, severe perianal Crohn's or complex fistulas

In almost every case, the intention is for it to be temporary, with reversal planned 8–12 weeks later (or longer if chemotherapy follows the original operation).

• Protects the downstream anastomosis while it heals — the main benefit
• Reduces the consequences of a leak if one does occur — a leak in a defunctioned anastomosis is often clinically silent and resolves with no further intervention
• Temporary by design — most patients have it reversed once healing is confirmed
• Easier to manage than an end stoma for many patients — the output is liquid but the appliance is smaller and the reversal operation is simpler

A loop ileostomy is safe and well-tolerated, but a few things are worth knowing:

• Dehydration is the most common reason for early hospital readmission after ileostomy formation. The small bowel output is liquid and can be high-volume in the first few weeks — you need to drink more fluid than you might think (typically 2.5–3 litres per day, and more if output is high).
• Skin irritation around the stoma is common in the early weeks. Good appliance fit and barrier products from your stoma nurse address this.
• Stoma retraction, prolapse, or parastomal hernia can develop over time
• The stoma may become permanent in a small proportion of cases — if there is an anastomotic leak with stricture, recurrent disease, or general medical factors that prevent reversal. This is uncommon but worth knowing about.
• Reversal surgery itself carries small risks of leak, ileus, and wound complications.
• Body image and lifestyle adjustment — even temporarily, living with a stoma takes some getting used to. Most people find they adapt faster than they expected.

Loop ileostomy formation is usually performed as part of a larger planned operation. Before that surgery:

• A stoma nurse will see you — usually at the pre-admission visit — to mark the best position on your abdomen for the stoma. They consider where you wear your clothes and where the stoma will sit clear of skin folds. They will also begin teaching you about the appliance.
• Standard pre-operative preparation applies — see the Preparing for Hospital Admission guide.

If you are nervous about the idea of a stoma — most people are at first — it is worth knowing that the stoma nurses are very experienced at making it manageable. You will not be left to figure it out alone.

The loop ileostomy is created as part of your larger operation rather than as a standalone procedure. A short loop of distal small bowel is brought up through a small opening in the abdominal wall — usually at the marked stoma site — opened transversely, and the edges stitched to the skin. This step adds about 15–30 minutes to the main operation.

Recovery follows the pattern of the larger operation (typically a bowel resection — see the Bowel Surgery Aftercare guide).

Stoma-specific points:

• The stoma usually starts producing output within 24–72 hours of surgery
• Output is liquid initially and may be 1–2 litres per day. This gradually decreases as your body adapts over the first few weeks
• The stoma nurse provides hands-on teaching before you leave hospital — appliance changes, skin care, hydration, recognising dehydration
• You will not be discharged until you (or someone helping you) are comfortable changing the appliance

Detailed daily-life information is in the Stoma Care guide.

A post-operative review is arranged within 2–6 weeks of discharge. This review is provided at no charge.

Reversal is typically planned 8–12 weeks after the original operation, or around 4–6 months if chemotherapy follows. The reversal operation itself is described on the Closure of Ileostomy page.

Before reversal:

• A contrast study is performed to confirm the downstream anastomosis is intact (see the Preparing for Stoma Reversal guide)
• A planning visit with your surgeon is arranged

Reversal is a smaller operation than the original — usually a hospital stay of 2–4 nights, with most people back to normal activity within 3–4 weeks. The first few weeks of bowel function afterwards can be a little erratic — see the reversal preparation guide for what to expect.

Whether a defunctioning loop ileostomy is needed is decided case by case. It is recommended where the risk of anastomotic leak is meaningful (low anastomoses, particularly after pre-operative radiotherapy) or where the consequences of a leak would be severe. For very low anastomoses Mr Nguyen almost always defunctions — accepting the small additional intervention to protect you from the consequences of a leak.

Have questions about this procedure?

If you have questions or would like to be seen, Mr Nguyen consults at his rooms in Heidelberg and operates at Warringal Private and Epworth Eastern. A GP or specialist referral is needed to make an appointment.

Get in touch →