By Stan Deresinski, MD, FACP, FIDSA
Clinical Professor of Medicine, Stanford University
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 Gastroenterol2016;111:602-622.
Fifteen years ago the Infectious Diseases Society of America published a practice guideline for managing cases of infectious diarrhea — guidelines that are currently being updated. The American College of Gastroenterology has meanwhile released its own set of guidelines for dealing with infectious diarrhea. This set of guidelines does not cover Clostridium difficile infection and tends to emphasize protocols for cases in immune-competent adults.
Prophylaxis: There are few common and effective prophylactic measures to safeguard against infectious diarrhea. Probiotics, prebiotics and synbiotics are all not recommended for prophylactic use in this manner. Most recommendations for prophylaxis against infectious diarrhea are conditional, and the risk-benefit ratio varies significantly depending on patient background. There is, however, strong evidence to suggest that bismuth subsalicylate or antibiotic chemoprophylaxis can be considered, although the latter consideration can be used for only a limited duration in cases of high-risk travelers.
Diagnosis: Etiological diagnosis is the advised diagnostic route for epidemiological purposes. This is especially true in cases where antimicrobial treatment may be necessary, such as in cases of dysentery or moderate to severe diarrhea, as well as those in which the disease has persisted for more than a week. As microscopy, culture, and antigen testing each often fail to detect pathogens present, other FDA-approved tests like those reliant on nucleic acid amplification should be strongly considered as alternatives. Upon discovery of bacterial pathogens in culture, the guidelines do not recommend antibiotic susceptibility testing.
It should be noted that despite these recommendations being deemed “strong,” they are uniformly based upon narrow evidentiary bases.
Treatment: Fluids and salts in most individuals’ diets can be easily substituted with juice, sports drinks, water and salted crackers. Elderly individuals with severe diarrhea or travelers with cholera-like watery diarrhea are advised to intake balanced electrolyte solutions. Though probiotics and prebiotics are, again, not recommended during treatment, there is evidence that bismuth subsalicylate can benefit those with mild to moderate diarrhea. Adjunctive loperamide, an antidiarrheal, may be recommended for travelers, particularly if they are receiving antibiotic therapy for acute infectious diarrhea. Despite this, the guidelines do not recommend antimicrobial agents unless the patient is a traveler in which the chance of bacterial origin is “high enough to justify” the risks of antibiotic use. Conversely, among patients whom acquired the illness apart from a healthcare system, antibiotic use is strongly discouraged, as community-based acquisition is mostly etiologically viral. Each of the treatment recommendations is graded strong, and is based on either high or moderate levels of evidence.
Evaluation when symptoms persist: Lastly, according to guidelines, patients with persistent (lasting for 14-30 days) diarrhea are not recommended to undergo laboratory testing or endoscopic evaluation. This is a strong recommendation, but is based on a very narrow evidentiary base.