Bowel Obstruction With an Ostomy

A blocked stoma — bowel obstruction with an ostomy — means intestinal contents cannot pass through the bowel and out into the pouch. It may be partial (some output, wind or watery stool still gets through) or complete (no output and no flatus). Food-bolus blockage and adhesions are the commonest causes. Mild partial episodes sometimes settle, but complete obstruction, severe pain, vomiting or a dark, swollen stoma needs emergency assessment.

Medically reviewed by the OstomyPedia clinical editorial team. Last reviewed: 5 March 2025.

Obstruction is a mechanical problem: something is interfering with the normal onward movement of intestinal contents. In someone with a stoma the blockage can sit at the stoma itself, in the short segment of bowel immediately behind it, or much higher in the small bowel where loops have become kinked, trapped or narrowed. Where the blockage sits changes the symptoms, the speed of onset and the urgency. Always discuss any change in your stoma output or abdominal symptoms with your stoma care nurse or clinician.

What a blocked stoma actually means

The bowel does not stop working the moment a blockage forms. It continues to contract, which is why obstruction produces cramping, wave-like pain and, eventually, vomiting as contents back up. Fluid and gas accumulate behind the blockage, causing distension. In an ileostomy the output is normally liquid and plentiful, so obstruction tends to produce a striking change: output becomes watery, then mucus-like, then stops altogether, often within a few hours.

Partial versus complete obstruction

A partial obstruction allows a little gas or liquid to squeeze past the blockage. You may still see some output, though it is usually thinner and less predictable than normal, and you may pass a small amount of wind. A complete obstruction allows nothing past. The distinction matters clinically because partial blockages are far more likely to settle with conservative treatment, while complete obstruction carries a risk of perforation, dehydration and — if the blood supply is cut off — bowel ischaemia. Only a clinician can reliably tell the two apart, so treat any doubt as a reason to seek advice.

Why ileostomies block more often than colostomies

Ileostomies are formed from the small intestine, which has a narrower calibre and a more liquid content, so a compacted mass of food has less room to pass. Ileostomy patients are also more vulnerable to dehydration when output is lost, and dehydration itself slows the bowel. Colostomies — formed from the large bowel, which absorbs water and holds stool — tend to be more forgiving of fibrous food, but obstruction can still occur through adhesions, hernia or stricture.

Causes of bowel obstruction with a stoma

Obstruction arises through several distinct mechanisms, and identifying the cause shapes both treatment and prevention.

Food-bolus blockage

This is the commonest cause in ileostomy patients. Poorly chewed, high-fibre or bulky foods — mushrooms, celery, dried fruit, nuts, seeds, popcorn, raw cabbage and other brassicas, sweetcorn, and large pieces of meat — can clump into a mass that lodges at the narrowest point, usually just behind the stoma. Symptoms typically begin within a few hours of the meal.

Adhesions after abdominal surgery

Every abdominal operation causes scar tissue to form between loops of bowel and the abdominal wall. These fibrous bands can kink or compress the bowel at any time afterwards, sometimes years later. Adhesion-related obstruction is the leading cause of hospital admission for bowel obstruction in the general surgical population, and anyone with a stoma has already had at least one abdominal operation, so the risk is elevated. Adhesions cannot be seen on a plain X-ray and are often diagnosed at CT scan or inferred once other causes are excluded.

Parastomal and incisional hernia

A parastomal hernia is a bulge beside the stoma where bowel pushes through the abdominal wall; an incisional hernia develops along a surgical scar. Either can trap a loop of bowel and obstruct it. A hernia that becomes irreducible, painful or tender, with no stoma output and vomiting, raises the possibility of strangulation — a surgical emergency requiring immediate assessment. Hernias are also common without obstructing at all, so a bulge alone is not an emergency, but a painful, tense, non-reducible bulge is.

Stoma stenosis

Gradual narrowing of the stoma opening over months or years — from scarring, retraction, or changes at the skin surface — can restrict outflow enough to cause obstructive symptoms, often alongside a thin, forceful or spraying stream of output. Stenosis is usually detected at routine stoma review and may be managed by dilatation or, in some cases, revision.

Recurrent or active disease

People whose stoma was formed for colorectal cancer or Crohn’s disease can develop recurrent disease that narrows (strictures) or externally compresses the bowel. Radiation treatment to the abdomen can also leave a fibrotic stricture years later. These presentations tend to build slowly over weeks rather than hours, which is an important clue.

Less common causes

Severe constipation and faecal impaction, particularly in colostomy patients, can mimic obstruction; medicines such as opioids, iron and some antidepressants contribute. Volvulus (a twisted loop of bowel) and internal hernias occur less often but are surgical emergencies. Your clinical team will consider all of these during assessment.

Recognising the signs

Symptoms range from mild and transient to severe and life-threatening. Thinking in terms of partial and complete obstruction helps you judge urgency.

Partial obstruction

• Colicky abdominal pain that comes in waves
• Reduced, watery or unusually loose stoma output
• Abdominal bloating and distension
• Nausea, sometimes with a feeling of fullness
• Continued passage of small amounts of wind

Complete obstruction

• No stoma output and no flatus for four hours or more
• Severe, constant or progressively worsening abdominal pain
• Pronounced distension and a tense abdomen
• Vomiting, which may become faeculent as the obstruction progresses
• A swollen, tight stoma that produces nothing
• Fever, drowsiness, confusion or collapse in advanced cases

Red flags: severe pain, vomiting and a dusky or black stoma

A stoma that changes colour — becoming pale, dusky, purple-black or black — suggests the blood supply to that segment of bowel is compromised. This is a surgical emergency, not a matter for telephone advice, and warrants calling emergency services immediately. The same is true of severe unremitting pain, a rigid or silent abdomen, vomiting that will not stop, and fever with a stoma that has stopped working. These features point towards strangulation, perforation or ischaemia, where delay carries real risk.

What to do: a step-by-step approach

The right response depends on how severe the symptoms are and how long they have lasted.

Mild symptoms in the first hour or two

If you suspect a food-related partial blockage, symptoms are mild, and it is less than about two hours since they started, general measures that stoma care nurses commonly suggest include stopping solid food and sipping fluids gently, taking a warm bath to relax the abdominal muscles, changing position (lying on your side with knees drawn up, or gently rocking), and massaging the skin around the stoma in a circular motion. Removing the pouch to check that the stoma opening is not being compressed by the appliance is also reasonable. These are comfort measures, not a treatment protocol; if there is no improvement within one to two hours, or symptoms worsen at any point, seek medical advice.

When to contact your stoma care nurse

Your stoma care nurse is the best first contact for slowing output without vomiting, colicky discomfort that is manageable, a suspected food trigger, a change in stoma shape or size, or questions about diet and medicines. They know your history, can assess the stoma, and can escalate you to a surgical team if needed. Out of hours, NHS 111 or an urgent treatment centre can advise on the same-day route.

When to call emergency services

Call emergency services or attend an emergency department without delay for no output for four hours or more, severe or worsening pain, persistent vomiting, a hard or silent abdomen, fever, or a stoma that is dark, dusky, black or acutely swollen. Always tell the triage team that you have a stoma and when it last produced output — this information changes both the priority and the type of assessment you receive.

What happens in hospital

Assessment usually begins with history, examination and blood tests to check electrolytes, kidney function and markers of infection or ischaemia. An abdominal X-ray or CT scan confirms the diagnosis, identifies the level and likely cause, and looks for perforation or a compromised blood supply. Intravenous fluids correct dehydration, which is often marked in ileostomy patients, and a nasogastric tube may be used to decompress the stomach and relieve vomiting in complete obstruction.

Most adhesion-related obstructions settle with conservative management — fluids, bowel rest and observation — within 24 to 72 hours, and many food-bolus blockages near the stoma can be relieved by an experienced clinician. Surgery is reserved for obstruction that does not resolve, suspected strangulation or perforation, or obstruction caused by a hernia that needs repair.

Recovery after a blockage

After a blockage resolves, bowel function usually returns over a day or two, often starting with watery output and wind before settling back to your normal pattern. Output can be unusually high for a short period, so attention to hydration matters, particularly with an ileostomy. Your team may advise a temporary return to low-fibre, easily digested foods before gradually reintroducing your usual diet. Ask for a follow-up review with your stoma care nurse to identify the likely cause and reduce the chance of a repeat.

Preventing future blockages

Not every obstruction is preventable, but several measures reduce risk. Chewing food thoroughly matters more than any single dietary rule, especially with an ileostomy. New high-fibre foods should be introduced gradually and in small portions, particularly in the weeks after surgery. Adequate fluid intake keeps intestinal contents moving, and regular stoma reviews allow stenosis or a hernia to be detected early. Report any sustained change in output pattern, stoma shape or abdominal comfort to your stoma care nurse promptly rather than waiting for a routine appointment.

Special situations

Living with an ileostomy

Because ileostomy output is liquid and losses can be large, dehydration is the main complication to watch for during and after a blockage. Signs include dark, reduced urine, thirst, dizziness on standing and headache. Discuss any concerns about fluids and electrolytes with your clinician rather than trying to manage them alone.

Living with a colostomy

Colostomy obstruction may develop more slowly, with constipation and overflow diarrhoea before complete cessation of output. Any colostomy that stops working for more than a couple of days, or that is accompanied by vomiting or severe pain, should be reviewed.

Urostomies

A urostomy diverts urine, not stool, so bowel obstruction is not a urostomy-specific problem. However, anyone who has had pelvic surgery or radiotherapy may still develop adhesions, and abdominal pain with no urine output is an emergency in its own right.

The bottom line

Bowel obstruction is a recognised complication of living with an ostomy, and it is manageable when identified early. Learning to distinguish a mild food-related slowdown from a true mechanical obstruction — and knowing when to call your stoma care nurse versus emergency services — is one of the most useful skills any ostomate can develop. Always consult your stoma care nurse or clinician about any concern regarding your stoma output or abdominal symptoms; timely advice can prevent a minor problem from becoming a serious one.