ConditionDigestive system
Ogilvie Syndrome (Acute Colonic Pseudo-Obstruction)
Ogilvie syndrome, or acute colonic pseudo-obstruction, is a sudden, severe swelling of the large intestine that looks like a bowel blockage but has no physical obstruction. The colon's muscle simply stops pushing contents along. It mostly affects older or seriously ill people in hospital, often after surgery such as a hip replacement or cesarean delivery. Most cases settle with supportive care, a medicine called neostigmine or colonoscopic decompression, but an overstretched colon can burst, so it needs close monitoring.
Also called: Acute colonic pseudo-obstruction, ACPO, colonic ileus, acute megacolon (non-toxic)
At a glance
- What it is
- Massive dilation of the colon without any physical blockage.
- Who gets it
- Older adults and people in hospital after surgery, injury or serious illness.
- Main signs
- Rapidly swelling, tight belly over 3 to 5 days, often still passing some gas or stool.
- Diagnosis
- CT scan to rule out a real blockage and measure the colon.
- Treatment
- Supportive care, then neostigmine or colonoscopic decompression; surgery if the colon perforates.
- Main danger
- Perforation when the cecum stretches beyond about 12 cm (4.7 inches).
When to get help
Call 911 or go to the ER
- A hugely swollen, tense belly with severe pain, fever, a racing heart or low blood pressure (possible perforation)
- Sudden worsening pain or tenderness all over the belly in someone with known colonic dilation
See a doctor within a day or two
- A rapidly enlarging belly in a hospital patient or nursing home resident, especially after surgery: tell the nurse or doctor immediately
- Belly swelling with vomiting and no bowel movement for several days in an older adult
Book a routine appointment
- Repeated episodes of bowel swelling and constipation, which may suggest a chronic motility disorder
What Ogilvie syndrome is
The colon moves its contents along by coordinated contractions controlled by the autonomic nervous system. One branch (parasympathetic) speeds the gut up, and the other (sympathetic) slows it. In Ogilvie syndrome, illness, surgery, medicines or metabolic upset are thought to tip this balance toward the sympathetic side. The colon stops contracting, gas and fluid build up, and it swells, usually most in the cecum and right colon.
The condition is named after Sir Heneage Ogilvie, a British surgeon who described it in 1948. "Pseudo-obstruction" means it looks like a blockage on scans and examination, but nothing is physically blocking the bowel.
It differs from related conditions:
| Condition | Key difference |
|---|---|
| Mechanical bowel obstruction | A real blockage such as a tumor, twist or scar tissue |
| Ileus | Paralysis mainly of the small bowel (and often stomach) after surgery |
| Toxic megacolon | Dilation from severe colitis, with fever and bloody diarrhea |
| Chronic intestinal pseudo-obstruction | Long-term, recurrent motility failure, often from childhood |
Causes and risk factors
Ogilvie syndrome almost always happens in someone who already has another serious problem:
- Surgery: orthopedic operations (especially hip and knee replacement and spine surgery), cesarean delivery, heart surgery and kidney transplant
- Trauma: fractures and spinal injuries
- Serious illness: infections and sepsis, heart attack, heart failure, stroke, respiratory failure
- Neurological conditions: Parkinson's disease, dementia, multiple sclerosis, spinal cord injury
- Electrolyte problems: low potassium (hypokalemia), low magnesium, low or high calcium
- Medicines: opioids, anticholinergics, antipsychotics, tricyclic antidepressants, calcium channel blockers, clonidine
- Other: kidney failure, hypothyroidism, long periods of bed rest
Most patients are over 60, and men are affected slightly more often.
Symptoms
- Abdominal distention, usually developing over 3 to 5 days and becoming dramatic
- crampy or constant belly pain, often milder than the swelling suggests
- nausea and vomiting
- constipation, though about half of patients still pass some gas or stool, which can be misleading
- a drum-like, hollow sound when the belly is tapped
- breathing difficulty in severe cases, as the swollen bowel pushes up on the diaphragm
Fever, severe tenderness, a fast heart rate and rising white cell counts suggest that the bowel wall is losing blood supply or has perforated.
How it is diagnosed
- Abdominal X-ray: shows a hugely dilated colon, often up to the rectum or a cutoff around the splenic flexure.
- CT scan: the key test. It confirms that there is no tumor, twist (volvulus) or other blockage, measures the cecum and looks for signs of ischemia or perforation.
- Blood tests: electrolytes (potassium, magnesium, calcium), kidney and thyroid function, blood count and lactate.
- Stool tests: for C. difficile infection if there is diarrhea, since this can cause toxic megacolon instead.
The width of the cecum is closely monitored. Perforation risk rises when it exceeds about 12 cm (4.7 inches) and when dilation persists for more than about 6 days.
Treatment
Supportive care (first 24 to 72 hours)
For a cecum under about 12 cm without signs of ischemia, most guidelines recommend starting with:
- nothing by mouth and IV fluids
- a nasogastric tube to drain the stomach, and a rectal tube to release gas
- correcting potassium, magnesium and other electrolytes
- stopping or reducing opioids, anticholinergics and other drugs that slow the gut
- treating the underlying illness
- getting the patient up and walking, or changing position frequently (lying face-down or knee-chest positions can help release gas)
- daily belly examinations and X-rays
This resolves the problem in a large proportion of patients.
Neostigmine
If there is no improvement, or the colon is very wide, doctors give neostigmine, a drug that boosts the parasympathetic signal to the bowel. It is given through a vein with heart monitoring, because it can slow the heart rate sharply, and atropine is kept ready. Many patients pass gas and stool within minutes, and studies show success in most cases. It is avoided in people with a mechanical blockage, certain heart rhythm problems, severe asthma or recent bowel surgery.
Colonoscopic decompression
If neostigmine fails or cannot be used, a gastroenterologist passes a colonoscope to suction out gas and may leave a decompression tube. This is effective, but the condition comes back in a significant minority of people, and a repeat procedure may be needed.
Surgery
Surgery is reserved for perforation, signs of bowel ischemia or failure of other treatments. Options include removing the damaged section of colon, often with a temporary stoma, or a cecostomy (a tube into the cecum through the belly wall) in very frail patients.
Complications and outlook
Perforation and ischemia occur in a small percentage of patients and carry a high risk of death, mostly because patients are already seriously ill. With early recognition and treatment before perforation, most people recover fully within days, and the colon returns to normal function. Recurrence is possible, especially if the underlying risk factors persist.
Frequently asked questions
What causes Ogilvie syndrome?
It is caused by a temporary failure of the colon's nerve control, usually in someone who is already unwell. Common triggers are surgery (especially hip, knee, spine or cesarean surgery), infections, heart or lung illness, electrolyte imbalances and medicines such as opioids. Often several triggers combine.
How is Ogilvie syndrome different from a bowel obstruction?
In a bowel obstruction, something physically blocks the intestine, such as a tumor, scar tissue or a twist. In Ogilvie syndrome the colon is wide open but its muscle has stopped working. A CT scan tells them apart, which is essential because treatment is different.
How is Ogilvie syndrome treated?
Treatment starts with resting the bowel, IV fluids, tubes to release gas, correcting electrolytes and stopping drugs that slow the gut. If that fails, intravenous neostigmine under heart monitoring usually works. Colonoscopic decompression and, rarely, surgery are used when other measures fail or the colon perforates.
Is Ogilvie syndrome life-threatening?
It can be if the colon overstretches and bursts, which is why doctors measure it closely and act early. Most patients recover with treatment. The risk of death is mainly linked to perforation and to the serious underlying illness that triggered the condition.
How long does Ogilvie syndrome last?
With supportive treatment, many cases improve within 2 to 3 days. Neostigmine often works within minutes to hours. Cases that persist longer need decompression, because the risk of perforation rises when the colon stays dilated for about 6 days or more.
Sources
This guide was written from current patient and clinical guidance, including:
- American Society for Gastrointestinal Endoscopy: Guideline on the management of acute colonic pseudo-obstruction and colonic volvulus
- American Society of Colon and Rectal Surgeons: Clinical practice guidelines for colonic volvulus and acute colonic pseudo-obstruction
- Merck Manual Professional: Acute colonic pseudo-obstruction
- National Organization for Rare Disorders: Ogilvie syndrome