Diverticulitis and Ostomy Surgery

Diverticulitis — inflammation or infection of small pouches (diverticula) that bulge outward from the wall of the large bowel — is one of the more common reasons that an adult in the UK undergoes emergency or urgent colorectal surgery. In its mildest forms, diverticulitis is managed entirely without surgery. In severe or complicated cases, however, an operation may be necessary, and that operation sometimes results in a temporary or permanent stoma. Understanding why this happens, what the surgery involves, and what recovery looks like can help patients and their families feel more prepared.

Why Diverticulitis Sometimes Requires a Stoma

Most episodes of acute diverticulitis resolve with antibiotic treatment and bowel rest. Surgery becomes necessary when complications arise that cannot be managed conservatively. The key complications that may lead to stoma formation include:

• Perforation with peritonitis. A perforated diverticulum can spill bowel contents into the abdominal cavity, causing widespread infection (peritonitis). This is a life-threatening emergency requiring immediate surgery.
• Abscess formation. A large abscess that cannot be drained percutaneously (through the skin under imaging guidance) may require open or laparoscopic surgical drainage.
• Obstruction. Repeated episodes of diverticulitis can cause scarring that narrows the bowel lumen, leading to obstruction.
• Fistula formation. An abnormal connection between the bowel and another organ (most often the bladder or vagina) may require surgical repair.

In any of these emergency scenarios, the bowel is often too inflamed, contaminated, or fragile to be safely rejoined (anastomosed) at the time of surgery. Creating a stoma allows the bowel to heal without the risk of an anastomotic leak.

The Hartmann’s Procedure: The Most Common Operation

The operation most frequently performed for complicated sigmoid diverticulitis is the Hartmann’s procedure, first described in 1921. It remains a cornerstone of emergency colorectal surgery.

What Happens During the Operation

The surgeon removes the diseased segment of the sigmoid colon — the S-shaped section of the large bowel most commonly affected by diverticulitis. Rather than immediately joining the two cut ends of bowel, the surgeon:

1. Brings the upper end (descending colon) to the surface of the left side of the abdomen as an end colostomy.
2. Closes the lower end (the rectal stump) and leaves it inside the pelvis.

The result is a single-opening stoma on the abdomen through which solid or semi-solid stool passes into a pouching system. The closed rectal stump produces only small amounts of mucus.

Why Not Reconnect the Bowel Immediately?

In emergency surgery for peritonitis or heavy contamination, an immediate bowel join carries a significant risk of leakage, which can itself be fatal. Separating the operation into two stages — first creating the stoma, then reversing it once the patient has recovered — reduces this risk considerably. In elective settings, where the bowel can be properly prepared, a single-stage resection with immediate anastomosis is often possible and does not require a stoma.

Temporary Versus Permanent Stomas

When a Hartmann’s procedure is performed, the intention is usually for the stoma to be temporary. Once the acute illness has resolved, the patient has recovered sufficient strength, and any ongoing infection or inflammation has settled — typically after three to six months — a second operation (the Hartmann’s reversal or stoma reversal) reconnects the colon to the rectum.

However, studies suggest that reversal rates are lower than might be expected. Factors that reduce the likelihood of reversal include:

• Advanced age and significant frailty
• Multiple co-existing medical conditions (diabetes, cardiovascular disease, immunosuppression)
• Obesity
• Patient preference after adapting well to stoma life
• Technical difficulty due to a very short rectal stump

For these reasons, it is important that patients receive clear and honest information before surgery about the realistic probability that their stoma may become permanent. A specialist stoma care nurse is an invaluable source of support in navigating these conversations.

Elective Surgery and Stoma Formation

Not all stomas related to diverticulitis arise from emergencies. Some patients who have experienced repeated episodes of diverticulitis or who have a diverticular stricture undergo planned (elective) resection of the affected bowel segment. In the elective setting:

• The bowel can be prepared in advance.
• Infection and inflammation are typically absent.
• A primary anastomosis (immediate rejoining) is usually possible, meaning no stoma is required.
• If a stoma is considered wise — for example, to protect a low or technically challenging anastomosis — a defunctioning loop colostomy or ileostomy may be formed temporarily.

Recovery and Life With a Diverticulitis-Related Stoma

In Hospital

Following emergency surgery, patients typically spend several days to a week or more in hospital. A stoma care nurse will visit during this time to begin teaching pouch changing, skin care, and output management.

At Home

Full recovery from a Hartmann’s procedure can take two to three months. During this period:

• Stoma output will initially be loose, becoming more formed as diet normalises.
• Fatigue is common and activity should be gradually increased.
• A high-fibre diet (once the bowel has settled) and good hydration help regulate output.
• Regular community stoma nurse follow-up is essential.

Preparing for Reversal

If reversal is planned, patients will usually undergo imaging (such as a CT scan or contrast enema) to assess the rectal stump and confirm that the bowel has healed adequately. The reversal operation itself carries its own risks, including anastomotic leak, infection, and changes in bowel habit, and requires its own recovery period.

The Bottom Line

Diverticulitis leads to ostomy surgery in a minority of cases — predominantly those involving serious complications such as perforation or peritonitis. The Hartmann’s procedure is the standard emergency operation, producing an end colostomy that is often, though not always, reversed once the patient has recovered. Elective surgery for diverticular disease usually avoids stoma formation altogether. Anyone facing diverticulitis-related surgery should be assessed and supported by a specialist stoma care nurse both before and after the procedure, and should discuss their individual likelihood of stoma reversal openly with their surgical team.

Always consult your stoma care nurse or colorectal surgeon for advice tailored to your specific situation. This article is for general information only and does not replace personalised clinical guidance.