If you suspect you have a clostridium difficile (C. diff) infection, receiving a quick diagnosis and treatment can make all the difference in your outcome. Since C. diff infections range from virtually symptomless to fuliminant pseudomembranous colitis, receiving a quality exam is crucial to diagnosis. What follows is the typical manner in which C. diff infections are diagnosed, along with questions to ask your physician to help you understand the severity of your case.

Patient History

The diagnosis of C. diff diarrhea requires your doctor taking a careful history with a particular emphasis on antibiotic use during the previous three months. As some antibiotics are more often implicated in C. diff disease, knowing the type and duration of your antibiotic use can be helpful.

The doctor may ask you for a detailed description of your diarrhea, including its color, consistency, and frequency. This is an important detail in differentiating C. diff-related diarrhea from other causes. Other important factors include a history of fever, immunosuppression (from chemotherapy, HIV or other causes), a recent surgical procedure, recent stay in a healthcare facility, previous infection with C. diff, recent change in bowel habits, and the presence of abdominal symptoms.

Laboratory Testing

The most common laboratory test for C. diff disease is an enzyme immunoassay that detects the two toxins produced by the bacteria. This is a stool sample test that provides results in two to six hours and has a specificity of 93 to 100 percent. The sensitivity of the test is 63 to 99 percent, so false negatives can occur.

The “gold standard” for the diagnosis of C. diff disease is a cytotoxin assay, which also tests stool for the toxins released by the bacteria. This test is highly sensitive and specific, but it is difficult to perform and results are not available for 24 to 48 hours.

Blood tests are also important in the diagnosis of C. diff colitis, particularly as an indication of impending fulminant colitis. A sudden rise in the peripheral white blood cell count is an invaluable signal that progression to shock or toxic megacolon is imminent.

Flexible sigmoidoscopy and colonoscopy

A flexible sigmoidoscopy is an examination where a fiberoptic tube with a light and camera on its end is inserted into the rectum and the sigmoid colon. In most people with C. diff colitis, pseudomembranes will be visible in the rectum and sigmoid colon.

Radiology

X-ray examinations and computed-tomography (CT) examinations of the abdomen will occasionally demonstrate thickening of the wall of the colon due to inflammation, but these x-ray findings are non-specific, revealing only that colitis is present but not its cause (e.g. C. diff). They may be used to rule out other conditions, such as intestinal blockage.

Suggested questions

Can I have C. diff even if I haven’t been admitted to a hospital recently?

What are the treatment options available if I’ve contracted C. diff?

(If you were being treated for another infection) Is there an antibiotic that is safe to take while you’re treating my C. diff infection?