Photo by CDC PHIL, Illustration by WC Lockwood

Clostridium difficile (C-diff) is bacteria found throughout nature but not part of the normal bacteria (flora) of the bowel. However, according to S.J. McPhee and M.A. Papadakis in "Current Medical Diagnosis and Treatment," C-diff colonizes the colon of about 3 percent of healthy adults and 20 percent of hospitalized patients. C-diff spreads through the fecal-oral route when fecal-contaminated hands touch an object or surface, leaving bacteria, and then another person touches the contaminated item and then the mouth or food.

Beginning Infection

Once inside the bowel, C-diff begins to multiply by releasing spores. If a person is healthy, the other bacteria in the bowel will keep C-diff in balance, but if the person is weak, older or immunocompromised and is receiving antibiotics (such as clindamycin, ampicillin, cephalosporins or fluoroquinolones), the normal bacteria may begin to die, allowing C-diff, which is resistant to many antibiotics, to multiply rapidly.



As C-diff multiplies, it releases toxins A and B and enzymes, which damage the cells in the mucosal lining of the colon, especially in the lower part of the colon and the rectum. The inside of the colon becomes irritated and swollen (colitis) and begins to erode away as ulcerations form, causing cramping and diarrhea. In response to the infection, the body produces fever and increased white blood cells to fight the infection. Debris from the injured lining and white blood cells form pus and patches called pseudomembranes in the colon.


According to Mayo Clinic, those with mild infections may have 2 or 3 watery stools daily, but as the infection worsens, stools may increase to 10 to 15, causing dehydration. The mucosal lining of the colon contains blood vessels, and the toxins and enzymes make vessels more permeable, so blood may leak into the bowel, or the ulcerations may erode vessels away, causing bloody stools. C-diff can also enter the blood stream, the first step in sepsis, a life-threatening infection.


With sepsis, the body produces an inflammatory response to the C-diff in the blood, causing the heart rate to increase. The white blood cell count continues to rise and the oxygen level in the blood decreases, making the person short of breath and sometimes confused. If bacteria overwhelm the body, the blood pressure begins to fall so low that the organs don't receive enough blood and oxygen, and the organs (such as the lungs and kidneys) begin to fail. The colon may begin to enlarge (megacolon) and may perforate, spilling fecal material and bacteria throughout the abdomen and spreading the infection.


Treatment is usually 10 days of oral antibiotics (metronidazole or vancomycin) to which C-diff is sensitive. However, according to "Current Medical Diagnosis and Treatment," severe or recurring infection requires longer treatment of 6 weeks. With sepsis, the person may need intravenous fluids and intravenous metronidazole at high doses for longer periods of time or until symptoms resolve. If megacolon or perforation occurs, surgical repair and sometimes removal of all or part of the colon may be necessary.


Identifying an infection early and immediately stopping the antibiotic that is causing the C-diff infection will resolve symptoms, according to the Centers for Disease Control and Prevention, in about 23 percent of those infected. Deaths from C-diff sepsis are rare.