By Stan Deresinski, MD, FACP, FIDSA

Clinical Professor of Medicine, Stanford University

Dr. Deresinski reports no financial relationships relevant to this field of study.

SYNOPSIS: The American College of Gastroenterology has developed a guideline dealing with the management of immunocompetent adults with acute infectious diarrhea, other than that due to Clostridium difficile infection.

SOURCE: Riddle MS, DuPont HL, Connor BA. ACG clinical guideline: Diagnosis, treatment, and prevention of acute diarrheal infections in adults. Am J Gastroenterol 2016;111:602-622.

A practice guideline for the management of infectious diarrhea was published by the Infectious Diseases Society of America (IDSA) 15 years ago an update is in progress. In the meantime, the American College of Gastroenterology (ACG) has now produced its guideline on the subject. This guideline focuses on immune-competent adults and does not consider Clostridium difficile infection.

Prophylaxis. Probiotics, prebiotics, and synbiotics (which are a combination of both) are not recommended. This recommendation is “conditional,” meaning that uncertainty exists regarding the risk-benefit ratio, and based on low-level evidence. Based on high levels of evidence, a strong recommendation is made that bismuth subsalicylate or antibiotic chemoprophylaxis may be considered, with the latter limited to short-term use in high-risk travelers.

Diagnosis. An attempt at etiologic diagnosis is recommended for epidemiologic purposes (e.g., with concern about transmission and during outbreaks) and in circumstances in which antimicrobial treatment may be indicated. The latter include patients with dysentery, those with moderate to severe disease, and those whose illness has persisted for more than seven days. Since culture, microscopy, and antigen testing frequently fail to detect a pathogen, other culture-independent techniques, such as the use of FDA-approved nucleic acid amplification tests, should be considered. When bacterial pathogens are recovered in culture, antibiotic susceptibility testing is not recommended. Note that while most of these recommendations are graded as strong, they are all based on low or very low levels of evidence.

Treatment. Fluid and salts can be replaced in most individuals with juice, sports drinks, water, and salted crackers. Balanced electrolyte solutions are recommened for elderly individuals with severe diarrhea and in any traveler with cholera-like watery diarrhea. Probiotics and prebiotics are not recommended in the acute stage of illness, but bismuth subsalicylate may provide benefit in those with mild to moderate illness. Adjunctive loperamide is recommended for travelers receiving antibiotic therapy for acute diarrhea. However, antimicrobial administration is not routinely recommended except for travelers in whom the likelihood of a bacterial etiology is “high enough to justify the potential side effects of antibiotics.” In contrast, antibiotic administration is discouraged in patients with community-acquired diarrhea — which is most often caused by viral pathogens. All the treatment recommendations are graded as strong and are based on moderate to high levels of evidence.

Evaluation When Symptoms Persist. Laboratory testing and endoscopic evaluation is not recommended for those with persistent diarrhea (defined as lasting for 14-30 days). While this is a strong recommendation, it is based on very low levels of evidence.

COMMENTARY

This guideline is useful, but it will be interesting to see the degree to which the IDSA guideline currently under development differs — especially with regard to diagnostics. While most of the ACG recommendations are graded as strong, it is discouraging that the majority are made based on low levels of evidence.