Diverticulitis occurs when diverticula or small, abnormal sacs in the large intestine, become infected and inflamed. According to the American College of Gastroenterology (ACG), about 10 to 25 percent of patients with diverticulosis (a condition characterized by the presence of diverticula) will eventually develop diverticulitis.
The symptoms of diverticulitis depend on the degree of inflammation and the presence of any complications. The most common signs and symptoms of the condition are tenderness, pain and an increased level of white blood cells. Other symptoms include constipation or diarrhea, nausea and vomiting. Peritonitis is the most serious complication of diverticulitis. It occurs when an abscess or sac ruptures or infection leaks out of the abscess and spills into the abdominal cavity.
Diverticulitis is usually diagnosed based on medical history, physical examination and blood tests. Most patients display classic signs and symptoms. Therefore, diagnostic imaging tests are often unnecessary. However, certain imaging tests (e.g., CAT scan, ultrasound) may be used in some cases.
The focus of treatment is clearing the infection and inflammation, resting the colon and preventing or minimizing complications. Bed rest, liquid or low-fiber diets and antibiotics are the typical treatment regimen. In most cases, the symptoms go away after three to four days of antibiotic therapy, though antibiotics will be required for a longer period. Few diverticulitis patients require surgery. When surgery is required, the diseased region of the colon is removed and the healthy sections are joined together to allow normal bowel function. Patients with large diverticular abscesses may require a temporary colostomy and reanostomosis as a later operation.
Dietary changes, exercise and good bowel habits help to prevent diverticulitis. The most important prevention method is the intake of plenty of fiber. This can be accomplished by eating more fiber-rich foods, such as fruits and vegetables, or taking fiber supplements.
About diverticulitis
Diverticulitis is the presence of infected and inflamed diverticula, or small, bulging, abnormal sacs in the large intestine. When a patient has these sacs, the condition is called diverticulosis. The pouches develop mainly in the sigmoid colon, the last section of the large intestine before the rectum. These abnormal sacs usually form due to pressure against weak spots that develop within the colon wall. The diverticula may become infected. The infection can spread if the sac leaks or tears. Abscesses may form outside the colon and other nearby organs (e.g., bladder) may also be affected.
The large intestine absorbs water as it moves fecal matter into the rectum to be excreted from the body. The sigmoid colon, located on the left side of the body, empties into the rectum.
Diverticulitis occurs in people with diverticulosis, a common condition that often develops as people age. Diverticulosis occurs in about half of all Americans over the age of 60, according to the National Institutes of Health (NIH). However, research indicates that acute diverticulitis is becoming increasingly common in younger individuals. Among individuals with diverticulosis, about 10 to 25 percent of patients will develop diverticulitis, according to the American College of Gastroenterology.
Diverticulitis is associated with several complications, including:
Abscess. If not treated quickly, the infection may escape the diverticulum and form an abscess, which is a collection of pus and infected tissue. An abscess may cause the skin to redden and may be felt during a physical examination as a tender mass in the abdomen.
Obstruction. Diverticulitis may cause the intestinal wall to swell and repeated attacks may cause scar tissue to build up and the muscular layer to thicken. This can cause the bowel to narrow (stricture), preventing stool from passing through normally.
Fistula. When an abscess forms near another organ (e.g., bladder, small intestine, vagina, skin), it may erode and form an abnormal passageway, or fistula, between that organ and the colon. Fistulae form most commonly between the colon and bladder, often causing severe, persistent urinary tract infections. This occurs far more often in men than in women because the uterus separates the colon and bladder in women.
Peritonitis. Sometimes, an abscess from diverticulitis may rupture and the infection may spill into the abdominal cavity, causing peritonitis. This is a very serious complication that may be life-threatening, especially if the contents of the bowel spill out into the abdominal cavity.
Risk factors and causes of diverticulitis
Diverticulitis is caused by the infection and resulting inflammation of diverticula, or small abnormal sacs, in the large intestine. The diverticula may become infected when stool is caught in them. This may interrupt the blood flow to the diverticulum and allow bacteria to accumulate. Infection may also occur when the wall of a diverticulum erodes and forms a small tear. It was once believed that diverticulitis was caused when stool became trappedin the diverticula, but this is no longer believed to be true.
The most prominent risk factor for diverticulitis is diverticulosis (a condition characterized by the presence of diverticula). However, according to the American College of Gastroenterology (ACG), only 10 to 25 percent of patients with diverticulosis will ever develop diverticulitis. Other risk factors include eating a high-fat, low-fiber diet, inadequate exercise and frequent constipation.
The risk of developing both diverticulosis and diverticulitis increase with age. The body becomes less efficient at waste removal and the elasticity and strength of the colon decrease with age, especially in the sigmoid colon. However, diverticulitis may be more severe and may pose a greater chance of complications in patients under the age of 40 years.
One episode of diverticulitis increases the risk of more attacks. According to the ACG, about a third of patients who have had a first attack will have a second. Subsequent attacks are often more severe than the first are more likely to result in complications. They may be less likely to respond to medications and have a greater chance of requiring surgical treatment.
Signs and symptoms of diverticulitis
The symptoms of diverticulitis depend on the degree of inflammation and the presence of any complications. Attacks can occur suddenly and without warning. However, diverticulitis may also come on gradually, with symptoms fluctuating in intensity.
The most common symptoms of diverticulitis are tenderness and pain, usually at or around the site of inflammation. The lower left part of the abdomen (the sigmoid colon) is a common area of pain and tenderness in patients with diverticulitis.
However, pain and tenderness may occur elsewhere in the abdomen depending on the location of the inflamed diverticula. The pain is usually severe but may range from mild cramping to severe pain that inhibits movement. It may come and go or remain constant, or there may be a constant pain with intermittent periods of increased pain.
Other signs and symptoms include:
Constipation or diarrhea
Nausea and vomiting
Loss of appetite
Bloating
Chills
Dysuria (pain or difficulty when urinating)
Increased frequency and urgency of urination
Ileus (intestinal muscles do not move properly, causing a lack of bowel sounds)
Increased white blood cell count
Fever
Bleeding from the rectum is not usually associated with diverticulitis, but it may occur. Bleeding is more common when the sacs are not infected.
Patients who develop signs and symptoms of diverticulitis should contact their physician.
Diagnosis methods for diverticulitis
Diverticulitis is usually diagnosed based on medical history, physical examination and blood tests to check for infection. Most patients display classic signs and symptoms of diverticulitis, so diagnostic imaging tests are not typically necessary. However, certain imaging tests (e.g., CAT scans, ultrasound) may be used if the diagnosis is uncertain, complications are suspected, the patient has a weakened immune system or the symptoms do not respond to medical therapy. These tests may reveal complications such as thickening of the intestinal wall, inflammation outside the colon, fistulae and abscesses.
During the evaluation of medical history, patients will typically be asked about their bowel habits, symptoms, diet and any medications they may be taking, both prescription and over-the-counter. During the physical examination, the gastroenterologist or other physician may press on the abdomen to check for fullness or tenderness and perform a digital rectal exam. This exam involves inserting a gloved, lubricated finger into the rectum to check for bleeding, blockage or tenderness. Blood tests are used to check for signs of infection. In some cases, a fecal occult blood test may be used to check for signs of intestinal bleeding.
Diagnostic imaging tests may include:
Computed axial tomography (CAT) scan. A series of x-rays are taken from different angles to generate a three-dimensional image of the internal organs. Generally the preferred procedure when the diagnosis is uncertain or complications are suspected. A CAT scan may be assisted by a water-soluble contrast medium that may be taken orally, rectally and/or intravenously.
Ultrasound. Sound waves are used to produce images of the internal organs. Ultrasound may be used to check for complications and rule out other possible causes of the symptoms. Ultrasound imaging may also be used to assist in draining fluid collections from outside the colon.
Abdominal x-ray. Frequently used to rule out other possible causes of the symptoms (e.g., appendicitis). Although it is not generally recommended during a diverticulitis attack, barium may be used as a contrast medium to make the internal structures show up more clearly in these x-rays. A water-soluble contrast medium may be used instead because it is less likely to cause further irritation or inflammation.
Colonoscopy. A tiny camera attached to a thin tube is inserted through the rectum and into the colon. It is typically not used in severe cases because it may cause rupture. However, diverticular disease may make cancer more difficult to diagnose. Because of these factors, a colonoscopy is generally performed several weeks (usually 6 to 8 weeks) after symptoms have cleared to check for any signs of colorectal cancer. The procedure may be performed at regular intervals afterward as well.
Sigmoidoscopy. A thin tube is used to look into the rectum and sigmoid colon. In some patients, this may be used to identify whether a suspect mass is abnormal and possibly cancerous or an inflamed diverticulum.
Treatment options for diverticulitis
Treatment for diverticulitis focuses on clearing the infection, reducing inflammation, resting the colon and preventing or minimizing complications. In most cases, hospitalization is not required, unless signs and symptoms are severe (e.g., vomiting, fever above 100 degrees Fahrenheit [37.8 degrees Celsius], very high white blood cell count) or the patient is elderly, has an increased risk of complications or has a weakened immune system.
Antibiotics, given in pill form, are generally used to treat bacterial infection for patients treated outside the hospital. Patients who must be hospitalized generally receive intravenous antibiotics. In most cases, the symptoms go away after three to four days of antibiotic therapy. These medications are typically continued for seven to 10 days after symptoms clear to ensure that the infection is gone.
Pain medications, both over-the-counter and prescription, may be used. However many of these have a tendency to cause constipation and aggravate diverticulitis, so some physicians may not recommend them. Antispasmodics are occasionally used for some patients.
Bed rest is generally recommended for patients with diverticulitis. Patients should avoid activities that increase pressure in the abdomen (e.g., lifting, straining, bending). Patients are frequently placed on a clear liquid or low-fiber diet. This allows the inflammation to clear and the bowels to rest. Once the symptoms go away, patients can begin gradually adding fiber to their diet.
Few diverticulitis patients require surgery. Surgery may be recommended for a number of reasons, including:
Symptoms do not respond to medical treatment.
Complications are present.
Cancer cannot be ruled out.
The patient has a weakened immune system.
The patient has had two or more attacks. This is because subsequent attacks tend to be more serious and increase the chance of complications. Some physicians may recommend surgery following the first attack in patients under the age of 40 years for similar reasons.
The surgical treatment for diverticulitis is colon resection (anastomosis). The diseased region of the colon is removed and the healthy sections are joined together to allow normal bowel function. This procedure may be performed as an open (traditional) surgery involving a single long incision, or a laparoscopic surgery (using a device called a laparoscope for imaging) involving three or four tiny incisions.
If there is extensive infection or obstruction, it may be unsafe to rejoin the sections of the colon that were not removed. In these cases, a colostomy is performed. During this procedure, the colon is connected to a hole (stoma) that is created in the abdomen. Stool then empties into a pouch attached to the stoma. This allows normal eating and bowel movements. The stoma is usually closed and the sections of the intestine are reconnected in a second surgery 10 to 12 weeks after the first. However, the colostomy may be permanent in some patients.
Abscesses may clear up with antibiotics alone. However, they may require drainage using a catheter and needle inserted into the abscess through the skin. Large abscesses may require surgical removal. Fistulae may also be surgically removed. The diseased portion of the colon is typically removed at the same time. Peritonitis usually requires immediate, emergency surgery to clean the abdominal cavity and remove the diseased portion of the colon.
Surgery for diverticulitis is very safe. Complications are rare, but may include risks generally associated with anesthesia (e.g., allergic reaction, cardiac and breathing difficulties) and surgery (e.g., bleeding and infection). Risks specifically related to colon surgery include:
Injury to an organ
Injury to the blood vessels
Hernias through the surgical incisions
Breakdown of the anastomosis
Prevention methods for diverticulitis
Diverticulitis may be prevented by eating a diet high in fiber, drinking plenty of fluids, exercising and practicing good bowel habits. The most important prevention method is the intake of plenty of fiber and fluids. These substances increase the bulk of stools and make them softer and easier to move through the large intestine.
Patients may also be advised to avoid foods that may get caught in or irritate the diverticula, including nuts, popcorn hulls and large seeds (e.g., sunflower seeds). However, it is not clear if avoiding these foods will prevent symptoms.
Exercise helps to prevent diverticulitis by relieving the pressure in the colon and making it easier to pass stool. It is also important to listen to the needs of the body. Poor bowel habits increase the pressure in the colon. When feeling a need to have a bowel movement, patients are urged not to immediately find a toilet. A bowel movement should not be forced. It is best to allow plenty of time rather than straining the intestinal muscles. Stool softeners may be taken with plenty of water to relieve constipation.
Questions for your doctor about diverticulitis
Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following diverticulitis-related questions:
Why do you suspect I have diverticulitis?
What may have caused my diverticulitis?
Do I appear to have any complications?
What are my treatment options?
What is the chance I will have another attack?
Would you recommend surgery if I have more attacks?
What signs or symptoms should I be watching for after this infection clears up?
When will I be able to resume my normal activities?
How should I alter my diet?
Does a family history of diverticulitis increase my chances of developing this condition?
If you do not recommend pain medications, what would you suggest I do to relieve the discomfort?
