A volvulus is a loop of intestine that twists around itself and the tissue (called the mesentery) that holds it in place. This twisting pinches off blood flow to the affected segment of bowel and blocks anything from passing through, creating a medical emergency. The condition can happen at several points along the digestive tract, but the most common location by far is the sigmoid colon, the S-shaped section of the large intestine just above the rectum.
How the Twisting Causes Damage
Your intestines are anchored to the back wall of your abdomen by a fan-shaped sheet of tissue that carries blood vessels. When a section of bowel rotates around this anchor point, it acts like wringing a towel: the opening of the intestine gets sealed shut, and the blood vessels feeding that segment get compressed or cut off entirely. Gas and fluid build up in the trapped loop, stretching the bowel wall and further compromising circulation.
Without blood flow, the tissue begins to die. This is called bowel gangrene, and it dramatically raises the stakes. Mortality rates jump from as low as 0% in cases without gangrene to between 3.7% and 80% when gangrene develops. The wide range reflects how quickly someone gets treatment and how much bowel is affected. A bowel segment that has lost its blood supply can eventually perforate, spilling intestinal contents into the abdominal cavity and causing a life-threatening infection called peritonitis.
Types of Volvulus
Sigmoid Volvulus
This is the most common form in adults. The sigmoid colon is naturally mobile and loops back on itself, which makes it vulnerable to twisting, especially when the mesentery at its base is narrow. It most often affects older adults who are bedridden or have limited mobility and a long history of chronic constipation. Over years, chronic constipation causes the sigmoid colon to stretch and become redundant, creating a longer loop with more room to rotate. Residents of nursing homes and long-term care facilities are disproportionately affected.
Sigmoid volvulus is also more common in parts of Africa, where high-fiber diets combined with a naturally narrower mesenteric base in certain populations create anatomical conditions that favor twisting. The interplay of diet, anatomy, and gut motility means this condition has a distinctly different demographic profile depending on where in the world you look.
Cecal Volvulus
The cecum is the pouch-like beginning of the large intestine, in the lower right abdomen. In some people, the cecum isn’t firmly attached to the abdominal wall, which allows it to swing and twist. Cecal volvulus is less common than sigmoid volvulus and tends to occur in younger adults. Because it happens in a different part of the abdomen, it can be mistaken for appendicitis or other right-sided abdominal conditions.
Midgut Volvulus in Infants
Midgut volvulus is a distinct and urgent condition seen primarily in newborns and young children. It’s caused by intestinal malrotation, a birth defect where the intestines didn’t complete their normal rotation during fetal development. This abnormal positioning leaves the small intestine dangling from a narrow stalk of tissue, which can twist suddenly. The hallmark sign in a newborn is bright green (bilious) vomiting, which is considered midgut volvulus until proven otherwise. Other warning signs include abdominal swelling, bloody stool, and inconsolable crying. Older children with the same condition may have a less dramatic presentation: recurring belly pain, diarrhea, and poor weight gain over time.
Symptoms in Adults
The core symptoms are abdominal pain, a visibly swollen belly, vomiting, and an inability to pass gas or stool. About two-thirds of people experience a sudden, dramatic onset. The remaining third have a more gradual buildup, with cramping and bloating that worsens over hours or days.
As the condition progresses, fever develops, and the abdomen becomes increasingly tender. If the bowel has perforated by the time someone reaches a hospital, the belly is typically rigid and exquisitely painful to touch. In cases of severe distension, the swollen intestines can push up against the diaphragm, making it difficult to breathe, and blood pressure may drop as the body goes into shock.
How It’s Diagnosed
A plain abdominal X-ray is often the first step and can be surprisingly revealing. Sigmoid volvulus produces a characteristic “coffee bean sign,” a massively dilated loop of bowel bent into an inverted U shape that resembles a coffee bean on film. This single image is often enough to make the diagnosis.
When the X-ray is inconclusive, a CT scan provides more detail. Radiologists look for a “whirl sign,” a spiral pattern where the twisted bowel and its blood vessels wrap around each other, along with a clear transition point where normal bowel meets the obstructed segment. For infants with suspected midgut volvulus, an ultrasound with Doppler can reveal a “whirlpool sign” where the vein wraps around the artery at the twist point.
Treatment: Untwisting and Preventing Recurrence
For sigmoid volvulus without signs of dead bowel, the first-line approach is endoscopic detorsion. A flexible tube is passed through the rectum into the twisted segment, and the bowel is gently untwisted and decompressed. This procedure succeeds about 62% of the time. However, the problem with stopping there is that the bowel is very likely to twist again: recurrence rates after detorsion alone reach roughly 46%, with episodes recurring on average within about a year.
Because of this high recurrence rate, surgical removal of the sigmoid colon (sigmoidectomy) is recommended after successful untwisting, ideally during the same hospital stay. Surgery eliminates the redundant loop of bowel that caused the problem and effectively prevents future episodes. When performed on a non-emergency, planned basis, the procedure carries a complication rate of 0% to 12%.
About 5% to 25% of patients arrive at the hospital already showing signs of bowel death, perforation, or severe infection. These patients skip the endoscopic step entirely and go straight to emergency surgery. Roughly 38% of sigmoid volvulus cases ultimately require surgical intervention. The surgery involves removing the damaged segment and either reconnecting the healthy ends of the colon or, if the remaining tissue is too inflamed for a safe reconnection, creating a temporary colostomy where the bowel is diverted to an opening in the abdomen.
In patients who also have megacolon, a condition where the entire colon is abnormally dilated, removing just the sigmoid portion isn’t enough. A more extensive removal of the colon is needed because the volvulus tends to recur in whatever dilated segment remains.
For midgut volvulus in infants, the treatment is always emergency surgery. The bowel is untwisted, any abnormal tissue bands are divided, and the intestines are repositioned to prevent future twisting.
Why Timing Matters
Volvulus sits on a steep curve where outcomes worsen rapidly with delay. The bowel can tolerate a temporary interruption in blood flow, but once gangrene sets in, mortality climbs sharply. Gangrene develops in anywhere from 6% to over 90% of sigmoid volvulus cases depending on how long the twist has been present before treatment. The enormous range in that statistic tells the story: people who reach a hospital quickly tend to do well, while those who wait, sometimes because symptoms started slowly and were mistaken for constipation, face far more dangerous surgery and a harder recovery.