The term volvulus actually comes from the Latin word volvere, which means “to roll”.
So a volvulus is an obstruction caused by a loop of the intestine that rolls or twists
around itself and its surrounding mesentery, which is the tissue that attaches the intestine
to the back wall of the abdomen.
The three most common types of volvulus are a sigmoid volvulus, which happens in the the
last part of the large intestine, leading to the rectum; a cecal volvulus, which happens
in the beginning of the large intestine, and a midgut volvulus, which happens in the small
intestine.
Now, a sigmoid volvulus is the most common type of volvulus, and it can happen in a variety
of settings.
One classic one being pregnancy, because the growing fetus can cause displacement and twisting
of the colon.
It can also develop, though, in middle-aged and elderly individuals.
This can sometimes happen as a result of chronic constipation, where a big load of stool can
act like a pivot point around which the rest of the colon can twist.
Hirschsprung disease, a disease of the large intestine that causes severe constipation
or intestinal obstruction, therefore raises the risk for developing sigmoid volvulus.
In addition, there are also abdominal adhesions, where internal scar tissue creates a physical
attachment between two parts of the abdomen, which again serves as a pivot point around
which the colon can twist.
A cecal volvulus is usually found in young adults, and usually happens in individuals
who didn’t develop their abdominal mesentery normally during fetal development.
Since some mesentery contacts may be missing in these individuals, the colon can flop around
freely and any large object—like a baby in pregnancy or a load of stool in someone
constipated—can act as a pivot point in the cecum and cause the colon to twist.
Midgut volvulus is most commonly found in babies and small children and is the result
of abnormal intestinal development in fetuses.
In normal fetal development, the digestive tract starts as a straight tube from the stomach
to the rectum.
For a little while, a part of the intestine protrudes from the abdomen into the umbilical
cord.
Once the fetus reaches around 10 weeks, though, the intestine pulls back out of the umbilical
cord, and returns to the abdominal cavity and makes two turns, so that it is no longer
a straight tube.
Malrotation happens when the cecum and appendix, which are normally found in the lower right
side of the abdomen, stay in the upper right side.
Babies with malrotation can later develop twisting of the small intestine, which is
a midgut volvulus.
In any type of volvulus, a portion of the intestines becomes twisted and it pinches
the lumen shut and results in bowel obstruction, which prevents the normal passage of digested
food and water.
Sometimes, the mesentery can become so tightly twisted that blood flow to that part of the
intestine is cut off, which leads to infarction, or death of the intestinal wall.
This can cause a variety of symptoms ranging from mild bloating and constipation to severe
pain and bloody stools.
In fact, bowel infarction can also cause the intestinal wall to break down and allow the
bacteria in the gut to move into the body, which causes sepsis and the potential for
cardiovascular collapse.
Abdominal x-rays are usually used to diagnose volvulus.
These x-rays show the shape of the volvulus, which can look like a bent inner tube or a
coffee bean.
A barium enema can also be used to show a bird’s beak shape, enlarged at one end and
tapered at the other end, which is the point where the bowel is twisted.
A sigmoid volvulus is usually treated with sigmoidoscopy, an examination of the sigmoid
colon using a set of flexible tubes inserted through the anus.
If the tissues look normal and pink, the tubes untwist and decompress the colon to relieve
pressure.
A similar procedure that goes a bit further in, called a colonoscopy, examines the entire
colon and can occasionally be used to resolve a cecal volvulus.
But a midgut volvulus can’t be treated with colonoscopy, since it’s even further back
in the small intestine.
Normally surgery is recommended within two days of receiving treatment, or, in some cases,
surgery should be performed immediately, like if the bowel is severely twisted or if the
blood supply is cut off.
The normal surgical procedure involves untwisting the intestine, if it hasn’t been corrected
yet, and attaching the intestine up against the abdominal wall to prevent it from twisting
in the future.
In severe cases, such as infarction, pieces of the intestine have to be removed, a process
called bowel resection, before the intestine is reattached.
Aright, as a quick recap: a volvulus is a twist in the intestine and surrounding mesentery,
and it’s most commonly found in the sigmoid of middle-aged and older adults, the cecum
of young adults, and the midgut, or small intestine, of babies.
Volvulus results in bowel obstruction and can sometimes cause infarction, or death,
of the bowel tissues.
Volvulus is diagnosed using x-rays and is usually treated with surgery to remove part
of the bowel and attach the bowel up against the intestinal wall.
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