Diverticulitis is a common digestive disease which involves the formation of pouches within
the bowel wall.
This process is known as diverticulosis, and typically occurs within the large intestine,
or colon, although it can occasionally occur in the small intestine as well.
Diverticulitis results when one of these diverticula becomes inflamed.
People often have left lower quadrant abdominal pain and tenderness, fever, and an increase
white blood cell count.
They may also complain of nausea or diarrhea; others may be constipated.
The severity of symptoms depends on the extent of the infection and complications.
Less commonly, an individual with diverticulitis may have right-sided abdominal pain.
This may be due to the less common right-sided diverticula or a highly redundant sigmoid
colon.
Some patients report bleeding from the rectum.
Causes The cause of diverticulitis is unknown.
The development of colonic diverticulum is thought to be a result of raised intraluminal
colonic pressures.
The sigmoid colon has the smallest diameter of any portion of the colon, and therefore
the portion which would be expected to have the highest intraluminal pressure.
The claim that a lack of dietary fiber, particularly non-soluble fiber predisposes individuals
to diverticular disease was long accepted within the medical literature.
However, the first study to specifically test the theory has found that "A high-fiber diet
and increased frequency of bowel movements are associated with greater, rather than lower,
prevalence of diverticulosis."
Diet Foods such as seeds, nuts, and corn were,
in the past, thought by many health care professionals to cause or worsen diverticulitis.
However, there is no evidence that suggests the avoidance of nuts and seeds prevents the
progression of diverticulosis to an acute case of diverticulitis.
It appears that a higher intake of nuts and corn could in fact help to avoid diverticulitis
in adult males.
Pathophysiology Diverticulitis is believed to develop due
to changes inside the intestines including high pressures due to faulty contracting of
the intestines.
Most people with diverticulosis do not have any discomfort or symptoms; however, symptoms
may include mild cramps, bloating, and constipation.
Other diseases such as inflammatory bowel disease and stomach ulcers cause similar problems,
so these symptoms do not always mean a person has diverticulosis.
Diagnosis
People with the above symptoms are commonly studied with computed tomography, or CT scan.
The CT scan is very accurate in diagnosing diverticulitis.
In order to extract the most information possible about the patient's condition, thin section
transverse images are obtained through the entire abdomen and pelvis after the patient
has been administered oral and intravascular contrast.
Images reveal localized colon wall thickening, with inflammation extending into the fat surrounding
the colon.
The diagnosis of acute diverticulitis is made confidently when the involved segment contains
diverticulae.
CT may also identify patients with more complicated diverticulitis, such as those with an associated
abscess.
It may even allow for radiologically guided drainage of an associated abscess, sparing
a patient from immediate surgical intervention.
Other studies, such as barium enema and colonoscopy are contraindicated in the acute phase of
diverticulitis due to the risk of perforation.
Differential diagnosis The differential diagnosis includes colon
cancer, inflammatory bowel disease, ischemic colitis, and irritable bowel syndrome, as
well as a number of urological and gynecological processes.
Treatment Most cases of simple, uncomplicated diverticulitis
respond to conservative therapy with bowel rest.
People may be placed on a low residue diet.
This low-fiber diet gives the colon adequate time to heal without needing to be overworked.
Antibiotics If bacterial infection is suspected, antibiotics
may be used.
Despite being recommended by several guidelines, the use of antibiotics in mild cases of uncomplicated
diverticulitis is supported with only "sparse and of low quality" evidence, with no evidence
supporting their routine use.
Surgery Surgery is often not needed.
Complications, such as peritonitis, abscess, or fistula may require surgery, either immediately
or on an elective basis.
Whether the elective surgery should be performed is decided by external factors such as the
stage of the disease, the age of the patient and his or her general medical condition,
as well as the severity and frequency of attacks or if the symptoms persist after a first acute
episode.
In most cases, the decision to perform elective surgery is taken when the risks of the surgery
are smaller than the ones resulting from complications of the condition.
Elective surgery may be performed at least six weeks after recovery from acute diverticulitis.
Emergency surgery is necessary for people whose intestine has ruptured; intestinal rupture
always results in infection of the abdominal cavity.
During emergency diverticulitis surgery, the ruptured section is removed and a colostomy
is performed.
This means that the surgeon will create an opening between the large intestine and the
surface of the skin.
The colostomy is closed in about 10 or 12 weeks in a subsequent surgery in which the
cut ends of the intestine are rejoined.
The first surgical approach consists in the resection and primary anastomosis.
This first stage of surgery is performed on patients with a well vascularized, nonedematous
and tension-free bowel.
The proximal margin should be an area of pliable colon without hypertrophy or inflammation.
The distal margin should extend to the upper third of the rectum where the taenia coalesces.
Not all of the diverticula-bearing colon must be removed, since diverticula proximal to
the descending or sigmoid colon are unlikely to result in further symptoms.
Diverticulitis surgery can be done in two ways: through a primary bowel resection or
through a bowel resection with colostomy.
Both bowel resections may be done in the traditional way or by laparoscopic surgery.
The traditional bowel resection is made using an open surgical approach, called colectomy.
During a colectomy, the patient is placed under general anesthesia.
A surgeon performing a colectomy will make a lower midline incision in the abdomen or
a lateral lower transverse incision.
The diseased section of the large intestine is removed and then the two healthy ends are
sewn or stapled back together.
A colostomy may be performed when the bowel has to be relieved of its normal digestive
work as it heals.
A colostomy implies creating a temporary opening of the colon on the skin surface and the end
of the colon is passed through the abdominal wall and a removable bag is attached to it.
The waste will be collected in the bag.
However, most of the surgeons prefer performing the bowel resection laparoscopically mainly
because the postoperative pain is reduced and the patient's recovery is faster.
The laparoscopic surgery is a minimally invasive procedure in which three to four smaller incisions
are made in the abdomen or navel.
All colon surgery involves only three maneuvers that may vary in complexity depending on the
region of the bowel and the nature of the disease which are the retraction of the colon,
the division of the attachments to the colon and the dissection of the mesentery.
After the resection of the colon, the surgeon normally divides the attachments to the liver
and the small intestine.
After the mesenteric vessels are dissected, the colon is divided with special surgical
staplers that close off the bowel while cutting between the staple lines.
When excessive inflammation of the colon renders primary bowel resection too risky, bowel resection
with colostomy remains an option.
Also known as the Hartmann's operation, this is a more complicated surgery typically reserved
for life-threatening cases.
The bowel resection with colostomy implies a temporary colostomy which is followed by
a second operation to reverse the colostomy.
The surgeon makes an opening in the abdominal wall which helps clear the infection and inflammation.
The colon is brought through the opening and all waste is collected in an external bag.
The colostomy is usually temporary but it may be permanent depending on the severity
of the case.
Most of the time, several months later after the inflammation has healed, the patient undergoes
another major surgery during which the surgeon rejoins the colon and rectum and reverses
the colostomy.
Complications In complicated diverticulitis, bacteria may
subsequently infect the outside of the colon if an inflamed diverticulum bursts open.
If the infection spreads to the lining of the abdominal cavity,, this can cause a potentially
fatal peritonitis.
Sometimes inflamed diverticula can cause narrowing of the bowel, leading to an obstruction.
Also, the affected part of the colon could adhere to the bladder or other organ in the
pelvic cavity, causing a fistula, or abnormal connection between an organ and adjacent structure
or organ, in this case the colon and an adjacent organ.
Bowel obstruction Peritonitis
Abscess Fistula
Bleeding Strictures
Epidemiology Diverticulitis most often affects middle-aged
and elderly persons, though it can strike younger people as well.
Central obesity may be associated with diverticulitis in younger patients, with some being as young
as 20 years old.
In Western countries, diverticular disease most commonly involves the sigmoid colon – section
4.
The prevalence of diverticular disease has increased from an estimated 10% in the 1920s
to between 35 and 50% by the late 1960s.
65% of those currently 85 years of age and older can be expected to have some form of
diverticular disease of the colon.
Less than 5% of those aged 40 years and younger may also be affected by diverticular disease.
Left-sided diverticular disease is most common in the West, while right-sided diverticular
disease is more prevalent in Asia and Africa.
Among patients with diverticulosis, 10–25% will go on to develop diverticulitis within
their lifetimes.
References
External links Health and Disease Information on Diverticulitis
at Penn State University Diverticulosis and Diverticulitis at NIDDK
Diverticulitis at Mayo Clinic