Pseudomembranous colitis is an inflammation and swelling of the colon with severe diarrhea. It happens when there is an overgrowth of Clostridioides difficile (C. Diff) bacteria in the gut, which produce toxins. It usually stems from antibiotic use.

In the last 20 years, the incidence of Clostridioides difficile (C.difficile) infections has steadily increased. There are now 500,000 cases annually in the United States. Doctors associate C.difficile with hospital stays, as itoccurs in 13% of people hospitalized for 2 weeks and up to 50% of those who stay 4 weeks or more.

Keep reading to learn about pseudomembranous colitis, including its causes, treatment, and when people should seek medical attention.

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Pseudomembranous colitis refers to inflammation of the large intestine or colon.

This inflammation is characterized by the presence of yellow-white plaques that gather to form a pseudomembrane on the colon’s mucus lining. Typically, these plaques measure up to 2 cm in diameter in a healthy colon and are scattered over the lining. However, in serious cases of pseudomembranous colitis, they can cover the entire mucus membrane of the colon.

Doctors may also refer to the condition as antibiotic-associated colitis or C. difficile colitis. They associate it with an overgrowth of the bacterium Clostridioides difficile, usually shortened to C. diff.

Diagnosis of pseudomembranous colitis primarily involves stool tests. There are different types of stool tests for C.difficile — ones that suggest the presence of the bacteria and others that suggest infection by the bacteria.

The most common symptom of pseudomembranous colitis is diarrhea. However, an individual may also experience fever, abdominal cramping, and bloody stools.

In severe cases, a person can develop the following:

  • reactive arthritis, which is joint pain and swelling due to the infection
  • hypovolemia, a condition where the amount of liquid, or plasma, in blood falls
  • hypotension, or low blood pressure
  • protein-losing enteropathy, where protein leaks out of the intestinal cells
  • toxic megacolon, a life threatening condition where swelling and inflammation cause the colon to expand

In some cases, pseudomembranous colitis is a life threatening condition.

Typically, C.difficile infection causes pseudomembranous colitis. Many bacteria, including C.difficile, make up the normal flora in the intestines and colon. Taking antibiotics or other medications might disrupt bacterial flora causing C.difficile to rapidly multiply and outgrow other bacteria.

Doctors usually associate antibiotics, such as clindamycin, fluoroquinolones, and cephalosporins with C. difficile infection. However, it can happen with any type.

However, there is a wide range of potential causes, including:

  • Infections: Although C. difficile is the pathogen doctors most commonly link to the condition, other bacteria, viruses, and parasites might cause it too. These include Staphylococcus aureus, Escherichia coli O157:H7, and Cytomegalovirus.
  • Chemicals and medications: Various substances can injure the colon and predispose it to pseudomembranous colitis. These include nonsteroidal anti-inflammatory drugs (NSAIDs) and chemotherapy agents. Glutaraldehyde, a chemical used to sanitize endoscopes, can also cause problems if not adequately rinsed before use.
  • Ischemia: This happens when the blood flow to the colon becomes partially or completely blocked. It often affects older adults with multiple health conditions, such as cardiovascular disease, diabetes mellitus, or lung disease.
  • Inflammatory conditions: Individuals with inflammatory bowel disease, including Crohn’s disease and ulcerative colitis, can develop pseudomembranous colitis.
  • Behçet disease: This rare immune-mediated disease can lead to mucus membrane ulceration.

The most significant risk factor for developing pseudomembranous colitis is having a C.difficile infection.

C. difficile is often considered a nosocomial pathogen, meaning that a person can become infected during a hospital stay. It usually causes diarrheal illness in older adults who have taken antibiotics or had a stay in a healthcare facility.

Some other risk factors can include:

  • having prior C.difficile infection
  • antibiotic use
  • advanced age
  • having chemotherapy
  • recent gastrointestinal or abdominal surgery
  • having an inflammatory disease, such as Crohn’s disease or ulcerative colitis

The treatment for pseudomembranous colitis depends on the cause. For example, if doctors diagnose a C. difficile infection, they may prescribe antibiotics such as vancomycin or fidaxomicin, as first-line treatment. The dose and frequency depend on the patient’s characteristics and disease severity.

In 20% of cases, pseudomembranous colitis can return following treatment.

Another treatment option may include surgery. Doctors may consider a fecal microbiota transplant if the condition returns despite antibiotic therapy. This treatment involves implanting fecal material from a healthy donor to restore normal bacterial flora to the colon. Some small trials have shown its benefit. However, it is not yet a common therapy.

Supportive therapy, such as electrolyte and fluid replenishment, may be given to people who have become dehydrated as a consequence of this condition.

Sometimes it is not possible to prevent pseudomembranous colitis. However, if it results from a C. difficile infection, people can help prevent the condition by:

  • Practicing good hand hygiene. This means washing the hands frequently with soap and water, particularly after visiting a healthcare facility or using the bathroom.
  • Adhering to rules set by healthcare staff. Nurses may ask people to wear a gown or gloves when visiting family or friends who have C. difficile infection.
  • Cleaning surfaces with chlorine bleach. This is to ensure that spores produced by C. difficile do not linger on surfaces that other people may have contact with.
  • Practicing good antibiotic stewardship. This means that doctors should select appropriate antibiotics to treat any infections and optimize the dose and duration. It is also important that people only take antibiotics as prescribed, finish the entire course, and do not take antibiotics that a doctor has not prescribed for them.

People with a mild version of C.difficile colitis have a good prognosis.

In more severe cases, antibiotic therapy should be commenced soon, and typically within seven to 10 days, their condition should improve. In about 20% of cases, people may relapse after treatment has finished. People who relapse may experience many more episodes.

People with pseudomembranous colitis should follow their doctor’s advice during the recovery process. They should not take any over-the-counter medication, such as antidiarrheal drugs, without checking first. These medications could affect healing or increase the risk of complications.

It is also important to practice good hygiene and avoid sharing personal items, such as towels or washcloths.

If the individual has diarrhea, it is critical to drink enough fluids to avoid dehydration. Water is a good option. However, diluted fruit juice, teas, and clear soup also work well.

Doctors may also recommend replacing lost electrolytes by drinking sports drinks or oral rehydration solutions. Eating a balanced diet and incorporating certain foods during this recovery period can also help prevent further nutrient loss.

Learn more about foods to eat and avoid if someone has a C.difficile infection here.

If a person has any of the following symptoms, they should seek medical attention:

  • bloody stools
  • feeling dehydrated
  • severe abdominal cramping or pain
  • having more than five episodes of diarrhea within 2 days

Pseudomembranous colitis is a condition that causes inflammation in the colon. It can cause severe symptoms such as watery diarrhea, abdominal pain, and fever.

The condition has various causes. However, it often results from a C. difficile infection. Treatment focuses on resolving the underlying cause, which may require antibiotics.

People with pseudomembranous colitis should drink plenty of fluids and eat soft, easily digestible foods. It is also important to practice good hygiene and avoid sharing personal items. If symptoms are severe or do not improve, the person should seek medical attention.