This article is more than 5 years old. Information may no longer be current.
Recent laxative use should not preclude testing patients for C. difficile
Click Here to Manage Email Alerts
Clinical practice guidelines issued last year recommended against routinely testing patients for Clostridioides difficile if they have received a laxative within the previous 48 hours. But recent study findings showed no difference in the rates or severity of C. difficile infection, or CDI, among patients who received laxatives compared with those who did not, and researchers cautioned that the recent guidance “[does not] allow room for clinical judgement” in determining if a patient is infected.
“Given the absence of compelling data indicating that laxative administration precludes or decreases risk of CDI, the basis for the recommendation to exclude patients on laxatives from C. difficile testing is simply that both CDI and laxatives can cause diarrhea,” Nicole C. White, MD, from the division of infectious diseases at Beth Israel Deaconess Medical Center in Boston, told Infectious Disease News.
“However, the mere presence of a possible alternate explanation for diarrhea — laxative use — does not mean that a patient cannot also have, or is less likely to have, true CDI,” she said. “In fact, other well-established causes of diarrhea predispose patients to a higher risk of CDI —inflammatory bowel disease, enteral tube feeding, intensive cancer chemotherapy — but we wouldn’t recommend that such patients be excluded from CDI testing.”
White and her co-authors “full support” the recent guidelines issued by the Infectious Diseases Society of America and Society for Healthcare Epidemiology of America to limit CDI testing to patients with clinically significant diarrhea, but they believe the recommendation to exclude patients receiving laxatives from CDI testing should be “thoughtfully re-evaluated,” she said.
White suggested that instead of a “blanket one-size-fits-all testing restriction,” perhaps more guidance could be provided as to what constitutes meaningful laxative use and how to reconcile CDI risk factors, signs or symptoms with the recommended testing restriction.
‘A sick group of patients’
For their study, White and colleagues assessed 209 patients with new-onset diarrhea and a positive stool sample for C. difficile, 65 of whom received laxatives. They examined laxative use, severity of illness and clinical outcomes.
According to White, the study findings were “striking.”
They found no difference in the severity of illness or the rate of attributable adverse outcomes —including CDI recurrence, ICU stay, colectomy and death — between those who received laxatives and those who did not. According to White, the groups did not differ in markers of clinical severity, such as fever, hypotension, leukocytosis and colitis on imaging, and most patients in both groups met criteria for classification as having severe CDI by both IDSA-SHEA and European Society of Clinical Microbiology and Infectious Diseases criteria.
“This was a sick group of patients who were likely to have had true CDI rather than colonization because many of them met criteria for severe infection,” White explained. “If the patients receiving laxatives had been excluded from testing as recommended by the IDSA-SHEA guidelines, diagnosis of CDI would have been missed in nearly one-third of our cohort — the 31.1% who had received laxatives, 66.2% of whom met criteria for severe CDI by IDSA-SHEA scoring methods — including one death, one patient who required a colectomy, and seven patients who required treatment in an ICU due to CDI.”
Use clinical judgement
Dimitri Drekonja, MD, MS, IDSA spokesperson and associate professor of medicine in the University of Minnesota, said there should not be a “hard and fast rule” against ordering CDI testing for patients on laxatives.
“The guidelines do mention laxative use a few times and they discuss the fact that you should consider if you really want to be testing for C. difficile if there is an attributable cause for diarrhea — like laxatives. One of the things the guidelines suggest is, if you’re having diarrhea that is ‘clearly’ attributable to laxatives — and I guess ‘clearly’ is really in the eye of the beholder,” he told Infectious Disease News.
“People should be reminded that there should not be a hard and fast rule of ‘Oh, this patient is on laxatives? I cannot order C. difficile.’ If your suspicion is very high, I would not let the presence of a laxative having been taken stop me from ordering test,” Drekonja said.
Although findings in the study by White and colleagues indicate that a history of recent laxative use cannot be used as a surrogate for the absence of CDI and that a blanket testing restriction on this group of patients has the potential for harm, Drekonja said the guidelines are carefully worded and suggest a case-by-case basis.
“The guidelines do mention that some people have symptoms or attributing factors that are associated with the risk of C. difficile, which makes it difficult to exclude the possibility of C. difficile on clinical grounds alone. You have to take clinical judgment into account,” he said. – by Caitlyn Stulpin
References:
McDonald LC, et al. Clin Infect Dis. 2018;doi:10.1093/cid/cix1085.
White NC, et al. Clin Infect Dis. 2019;doi:10.1093/cid/ciz978.
Disclosures: Drekonja and White report no relevant financial disclosures. Please see the full study for all other authors’ relevant financial disclosures.