Pseudomembranous (SOO-doe-mem-bruh-nus) colitis, also called antibiotic-associated colitis or C. difficile colitis, is inflammation of the colon associated with an overgrowth of the bacterium Clostridium difficile (C. diff). This overgrowth of C. difficile is most often related to recent antibiotic use.
Signs and symptoms of pseudomembranous colitis may include:
- Diarrhea that can be watery or even bloody
- Abdominal cramps, pain or tenderness
- Pus or mucus in your stool
Symptoms of pseudomembranous colitis can begin as soon as one to two days after you start taking an antibiotic, or as long as several weeks after you finish taking the antibiotic.
When to see a doctor
If you are currently taking or have recently taken antibiotics and you develop diarrhea, contact your doctor, even if the diarrhea is relatively mild. Also, see your doctor any time you have severe diarrhea, with fever, painful abdominal cramps, or blood or pus in your stool.
Usually, your body keeps the many bacteria in your colon in a naturally healthy balance. However, antibiotics and other medications can upset this balance. Pseudomembranous colitis occurs when certain bacteria — usually C. difficile — rapidly outgrow other bacteria that normally keep them in check. Certain toxins produced by C. difficile, which are usually present in only tiny amounts, rise to levels high enough to damage the colon.
While almost any antibiotic can cause pseudomembranous colitis, some antibiotics are more likely to cause pseudomembranous colitis than others:
- Fluoroquinolones, such as ciprofloxacin (Cipro) and levofloxacin (Levaquin)
- Penicillins, such as amoxicillin and ampicillin
- Clindamycin (Cleocin)
- Cephalosporins, such as cefixime (Suprax)
Other medications besides antibiotics can sometimes cause pseudomembranous colitis. Chemotherapy drugs that are used to treat cancer may disrupt the normal balance of bacteria in the colon.
Certain diseases that affect the colon, such as ulcerative colitis or Crohn's disease, may also predispose people to pseudomembranous colitis.
C. difficile spores are resistant to many common disinfectants and can be transmitted from the hands of health care professionals to patients. Increasingly, C. difficile has been reported in people with no known risk factors, including people with no recent health care contact or use of antibiotics. This is called community-acquired C. difficile.
Factors that may increase your risk of pseudomembranous colitis include:
- Taking antibiotics
- Staying in the hospital or a nursing home
- Increasing age, especially over 65 years
- Having a weakened immune system
- Having a colon disease, such as inflammatory bowel disease or colorectal cancer
- Undergoing intestinal surgery
- Receiving chemotherapy treatment for cancer
Treatment of pseudomembranous colitis is usually successful. However, even with prompt diagnosis and treatment, pseudomembranous colitis can be life-threatening. Possible complications include:
- Abnormally low levels of potassium in your blood (hypokalemia), due to the loss of potassium during excessive diarrhea
- Dehydration leading to abnormally low blood pressure (hypotension), related to significant loss of fluids and electrolytes due to diarrhea
- Kidney failure, due to severe dehydration resulting from diarrhea
- A hole in your bowel (perforated colon), which can lead to an infection of your abdominal cavity
- Toxic megacolon, a rare but serious swelling of the colon, leaving it incapable of expelling gas and stool, which could cause your colon to rupture
In addition, pseudomembranous colitis may sometimes return, days or even weeks after apparently successful treatment.
Tests and procedures used to diagnose pseudomembranous colitis and to search for complications include:
- Stool sample. There are a number of different stool sample tests used to detect C. difficile infection of the colon.
- Blood tests. These may reveal an abnormally high white blood cell count (leukocytosis), which may indicate pseudomembranous colitis.
- Colonoscopy or sigmoidoscopy. In both of these tests, your doctor uses a tube with a miniature camera at its tip to examine the inside of your colon for signs of pseudomembranous colitis — raised, yellow plaques (lesions), as well as swelling.
- Imaging tests. If you have severe symptoms, your doctor may obtain an abdominal X-ray or an abdominal CT scan to look for complications such as toxic megacolon or colon rupture.
Treatment strategies include:
- Stopping the antibiotic or other medication that's thought to be causing your signs and symptoms, if possible. Sometimes, this may be enough to resolve your condition or at least ease signs, such as diarrhea.
- Starting an antibiotic likely to be effective against C. difficile. If you still experience signs and symptoms, your doctor may use a different antibiotic to treat C. difficile. This allows the normal bacteria to grow back, restoring the healthy balance of bacteria in your colon. You may be given antibiotics by mouth, through a vein or through a tube inserted through the nose into the stomach (nasogastric tube). Depending on your condition, doctors will use most often use metronidazole (Flagyl), vancomycin, fidaxomicin (Dificid) or a combination.
- Having fecal microbial transplantation (FMT). If your condition is extremely severe, you may be given a transplant of stool (fecal transplant) from a healthy donor to restore the balance of bacteria in your colon. The donor stool may be delivered through a nasogastric tube, inserted into the colon or placed in a capsule you swallow. Often, doctors will use a combination of antibiotic treatment followed by FMT.
Once you begin treatment for pseudomembranous colitis, signs and symptoms may begin to improve within a few days.
Researchers are exploring new treatments for pseudomembranous colitis, including alternative antibiotics and a vaccine.
Treating recurring pseudomembranous colitis
The natural occurrence of new, more-aggressive strains of C. difficile, which are more resistant to antibiotics, has made treating pseudomembranous colitis increasingly difficult and recurrences more common. With each recurrence, your chance of having an additional recurrence increases. Treatment options may include:
- Repeat antibiotics. You may need a second or third round of antibiotics to resolve your condition.
- Surgery. Surgery may be an option in people who have progressive organ failure, rupture of the colon and inflammation of the lining of the abdominal wall (peritonitis). Surgery has typically involved removing all or part of the colon (total or subtotal colectomy). A newer surgery that involves laparoscopically creating a loop of colon and cleaning it (diverting loop ileostomy and colonic lavage) is less invasive and has had positive results.
- Fecal microbial transplantation (FMT). FMT is used to treat recurrent pseudomembranous colitis. You'll receive healthy, cleaned stool in a capsule, nasogastrically or inserted into your colon.
Your primary care doctor can usually treat pseudomembranous colitis. Based on your signs and symptoms, you may be referred to a specialist in digestive diseases (gastroenterologist). If your signs and symptoms are particularly severe, you may be told to seek emergency treatment.
Here's some information to help you get ready for your appointment, and what to expect from your doctor.
What you can do
When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a specific test. Make a list of:
- Your symptoms, including any that seem unrelated to the reason for your appointment
- Key personal information, including major stresses, recent life changes and family medical history
- All medications, vitamins or other supplements you take, including the doses
- Questions to ask your doctor
Take a family member or friend along, if possible, to help you remember the information you're given.
Some basic questions to ask your doctor include:
- What's likely causing my symptoms?
- Other than the most likely cause, what are other possible causes for my symptoms?
- What tests do I need?
- Is my condition likely temporary or chronic?
- What's the best course of action?
- What are the alternatives to the primary approach you're suggesting?
- I have these other health conditions. How can I best manage them together?
- Are there restrictions I need to follow?
- Should I see a specialist?
- Are there brochures or other printed material I can have? What websites do you recommend?
Don't hesitate to ask other questions.
What to expect from your doctor
Your doctor is likely to ask you several questions, such as:
- When did you first begin experiencing signs and symptoms?
- Do you have diarrhea?
- Is there blood or pus in your stools?
- Do you have a fever?
- Are you having abdominal pain?
- Have your symptoms stayed the same or gotten worse?
- During the last several weeks, have you taken antibiotics, had a surgical procedure or been hospitalized?
- Is anyone at home sick with diarrhea, or has anyone at home been hospitalized in the last several weeks?
- Have you ever been diagnosed with diarrhea related to C. difficile or antibiotics?
- Do you have ulcerative colitis or Crohn's disease?
- Are you being treated for any other medical conditions?
- Have you traveled recently to areas with an unsafe water supply?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
What you can do in the meantime
While you're waiting for your appointment, drink plenty of fluids and stick to bland foods to help you cope with diarrhea.
Some research suggests that concentrated supplements of good bacteria and yeasts (probiotics) can help prevent C. difficile infection, but more studies are needed for their use in treating recurrences. They are safe to use and available in capsule or liquid form without a prescription.
To cope with the diarrhea and dehydration that can occur with pseudomembranous colitis, try to:
- Drink plenty of fluids. Water is best, but fluids with added sodium and potassium (electrolytes) also may be beneficial. Avoid beverages that are high in sugar or contain alcohol or caffeine, such as coffee, tea and colas, which can aggravate your symptoms.
- Choose soft, easy-to-digest foods. These include applesauce, bananas and rice. Avoid high-fiber foods, such as beans, nuts and vegetables. If you feel your symptoms are improving, slowly add high-fiber foods back to your diet.
- Eat several small meals, rather than a few large meals. Space the smaller meals throughout the day.
- Avoid irritating foods. Stay away from spicy, fatty or fried foods, and any other foods that make your symptoms worse.