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Clostridioides (formerly Clostridium) difficile–Induced Colitis

(Pseudomembranous Colitis; C. diff)


Larry M. Bush

, MD, FACP, Charles E. Schmidt College of Medicine, Florida Atlantic University

Reviewed/Revised Jun 2023

Clostridioides difficile (C. difficile)–induced colitis is an inflammation of the large intestine (colon) that results in diarrhea. The inflammation is caused by toxin produced by C. difficile bacteria and usually develops after people take antibiotics that enable these bacteria to grow in the intestine.

  • C. difficile–induced colitis usually occurs after taking antibiotics.

  • Typical symptoms range from slightly loose stools to bloody diarrhea, abdominal pain, and fever.

  • Doctors test the stool and sometimes use a viewing tube to examine the large intestine of people who have symptoms of C. difficile–induced colitis.

  • Most people who have mild C. difficile–induced colitis get better after the antibiotic that triggered the colitis has been stopped and another antibiotic is taken.

Did You Know...

  • Some healthy people have C. difficile bacteria living in their intestine.

Causes of C. diff Colitis

In C. difficile–induced colitis, the bacteria produce toxins that cause inflammation of the colon (colitis), usually after antibiotics are taken to treat an infection. Many antibiotics alter the balance among the types and quantity of bacteria that live in the intestine. Thus, certain disease-causing bacteria, such as C. difficile, can overgrow and replace the harmless bacteria that normally live in the intestine. C. difficile is the most common cause of colitis that develops after antibiotics are taken.

When C. difficile bacteria overgrow, they release toxins that cause diarrhea, colitis, and the formation of abnormal membranes (pseudomembranes) in the large intestine.

A deadlier strain of C. difficile has been identified in some hospital outbreaks. This strain produces substantially more toxin, causes more severe illness with greater chance of relapse, is easier to transmit, and does not respond as well to antibiotic treatment.

Almost any antibiotic can cause this disorder, but clindamycin, penicillins (such as ampicillin and amoxicillin), cephalosporins (such as ceftriaxone), and fluoroquinolones (such as levofloxacin and ciprofloxacin) are implicated most often. C. difficile–induced colitis can occur even after very brief antibiotic courses. C. difficile–induced colitis also may follow the use of certain cancer chemotherapy drugs.

C. difficile infection is most common when an antibiotic is taken by mouth, but it also occurs when antibiotics are injected into a muscle or given by vein (intravenously).

The risk of developing C. difficile–induced colitis and the risk that it will be severe increases with age. Other risk factors include

  • Having one or more other severe disorders

  • Staying for an extended time in the hospital

  • Living in a nursing home

  • Undergoing gastrointestinal surgery

  • Having a disorder or taking a medication that decreases gastric acidity

Sometimes the source of the bacteria is the person's own intestinal tract. C. difficile is commonly present in the intestines of newborns, healthy adults, and adults who are hospitalized. In these people, C. difficile typically do not cause illness unless they overgrow. However, these people can spread clostridia to at-risk people. Person-to-person spread can be prevented by meticulous hand washing Prevention of Infection Several measures help protect people against infection. Handwashing is an effective way of preventing the spread of infectious microorganisms from one person to another. Handwashing is particularly... read more Prevention of Infection .

People may also get the bacteria from pets or the environment.

Colitis caused by C. difficile infection rarely occurs unless people have recently used antibiotics. However, physically stressful events, such as surgery (typically involving the stomach or intestine), can likely lead to the same kind of imbalance among the type and quantity of bacteria in the intestine or can interfere with the intestine's intrinsic defense mechanisms, which, in turn, allows C. difficile infection and colitis to develop.

Symptoms of C. diff Colitis

Diagnosis of C. diff Colitis

  • Stool studies

  • Sometimes sigmoidoscopy or colonoscopy

Doctors suspect C. difficile–induced colitis in anyone who develops diarrhea within 2 months of using an antibiotic or within 72 hours of being admitted to a hospital.

The diagnosis is confirmed by using stool tests. Doctors do tests to detect toxins produced by C. difficile as well as a certain enzyme released by the bacteria. Doctors also do tests such as the polymerase chain reaction (PCR) technique Polymerase chain reaction (PCR) Genetic diagnostic technologies are scientific methods that are used to understand and evaluate an organism's genes. (See also Genes and Chromosomes.) Genes are segments of deoxyribonucleic... read more to detect the presence of the bacteria's genetic material (DNA).

A doctor can also diagnose C. difficile–induced colitis by inspecting the lower part of the inflamed large intestine (the sigmoid colon), usually through a sigmoidoscope Endoscopy Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope). In addition to examinations, doctors can use endoscopy to do biopsies and give treatment. Endoscopes... read more (a flexible viewing tube). If they observe a specific type of inflammation called pseudomembranous colitis, C. difficile–induced colitis is diagnosed. A colonoscope (a longer flexible viewing tube) is used to examine the entire large intestine if the diseased section of intestine is higher than the reach of the sigmoidoscope. These procedures, however, usually are not required.

Treatment of C. diff Colitis

  • Stopping use of the antibiotics causing the colitis

  • Antibiotics effective against C. difficile

  • For recurrences, antibiotics

  • For frequent recurrences, sometimes a fecal (stool) transplant

If a person with C. difficile–induced colitis has diarrhea while taking an antibiotic, the antibiotic is stopped immediately unless it is essential. After stopping the antibiotic, symptoms usually stop within 10 to 12 days. If the symptoms are severe or persist, people are usually given an antibiotic that is effective against C. difficile.

Most cases of C. difficile–induced colitis are treated with the antibiotic vancomycin or fidaxomicin, given by mouth. Fidaxomicin results in fewer recurrences of symptoms.

Medications (such as loperamide) that people sometimes take to slow the movement of the intestine and treat diarrhea should not be taken. Such medications may prolong or worsen the disorder by keeping the disease-causing toxin in contact with the large intestine.

Occasionally, C. difficile–induced colitis is so severe that the person must be hospitalized to receive intravenous fluids, electrolytes Overview of Electrolytes More than half of a person's body weight is water. Doctors think about water in the body as being restricted to various spaces, called fluid compartments. The three main compartments are Fluid... read more (such as sodium Overview of Sodium's Role in the Body Sodium is one of the body's electrolytes, which are minerals that the body needs in relatively large amounts. Electrolytes carry an electric charge when dissolved in body fluids such as blood... read more , magnesium Overview of Magnesium's Role in the Body Magnesium is one of the body's electrolytes, which are minerals that carry an electric charge when dissolved in body fluids such as blood, but the majority of magnesium in the body is uncharged... read more , calcium Overview of Calcium's Role in the Body Calcium is one of the body's electrolytes, which are minerals that carry an electric charge when dissolved in body fluids such as blood, but most of the body's calcium is uncharged. (See also... read more , and potassium Overview of Potassium's Role in the Body Potassium is one of the body's electrolytes, which are minerals that carry an electric charge when dissolved in body fluids such as blood. (See also Overview of Electrolytes.) Most of the body’s... read more ), and blood transfusions Overview of Blood Transfusion A blood transfusion is the transfer of blood or a blood component from one healthy person (a donor) to a sick person (a recipient). Transfusions are given to increase the blood's ability to... read more Overview of Blood Transfusion .

Rarely, surgery is required. For example, surgical removal of the large intestine (colectomy) may be needed in severe cases as a lifesaving measure.

Treatment of recurrences

Symptoms return in 15 to 20% of people with this disorder, typically within a few weeks of stopping treatment. The first time diarrhea returns, people are given another course of the same antibiotic. If diarrhea continues to return, they are given vancomycin or fidaxomicin, whichever one they have not been given yet, for several weeks.

A fecal (stool) transplant is an option for some people who have frequent recurrences. In this procedure, about a cup (about 200 to 300 milliliters) of stool from a healthy donor is placed in the person's colon. The donor's stool is first tested for microorganisms that can cause disease. The fecal transplant can be given as an enema, through a tube inserted through the nose into the digestive tract, or through a colonoscope Endoscopy Endoscopy is an examination of internal structures using a flexible viewing tube (endoscope). In addition to examinations, doctors can use endoscopy to do biopsies and give treatment. Endoscopes... read more . Doctors think that fecal material from a donor restores the normal balance of bacteria in the intestine of a person with C. difficile–induced colitis. After this treatment is used, symptoms are less likely to recur. A pill that contains healthy donor stool is also an effective treatment.

Bezlotoxumab is a monoclonal antibody Monoclonal Antibodies Immunotherapy is the use of medications that mimic or modify components of the immune system (such as tumor antigens and immune checkpoints—see also Overview of the Immune System) to fight disease... read more that is given by vein. It binds to one of the toxins produced by C. difficile. Giving bezlotoxumab plus standard antibiotic treatment can reduce the chances that diarrhea will recur.

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