What is the diagnosis and treatment for viral gastroenteritis?

From the Guidelines

Viral gastroenteritis should be managed primarily through oral rehydration, with adults consuming at least 2-3 liters of fluid daily, and symptom management using over-the-counter medications like acetaminophen and cautious use of anti-diarrheal medications like loperamide in adults. The diagnosis of viral gastroenteritis is based on the presence of symptoms such as watery diarrhea, abdominal cramps, nausea, vomiting, and sometimes fever, as outlined in the 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea 1.

According to the guidelines, most acute diarrhea episodes in previously healthy, immunocompetent people are of short duration and self-resolving, and are of viral or unknown etiology, and therefore, laboratory investigation is generally not warranted 1. However, factors such as epidemiologic and clinical features, immunocompromised status, and suspicion of an outbreak situation may justify laboratory testing 1.

For treatment, oral rehydration solutions such as Pedialyte can be used, and adults can consume clear fluids like water and clear broths 1. Over-the-counter medications like acetaminophen can help with fever and discomfort at standard dosing (650-1000mg every 6 hours, not exceeding 4000mg daily) 1. Anti-diarrheal medications such as loperamide may be used cautiously in adults (initial dose 4mg followed by 2mg after each loose stool, maximum 16mg daily) but should be avoided in children and if there's high fever or bloody stools 1.

Prevention of viral gastroenteritis can be achieved through general measures such as hand hygiene, proper food preparation and storage, avoidance of high-risk foods, and use of infection prevention and control measures in hospitals, childcare, and nursing home settings 1. The guidelines also recommend routine use of rotavirus vaccine in infants and typhoid and cholera vaccines for travelers when indicated 1.

It is essential to practice good hand hygiene with soap and water, especially after using the bathroom and before handling food, and to avoid preparing food for others while sick and for 2-3 days after recovery 1. Medical attention should be sought if symptoms are severe, if fluids cannot be kept down, if there's blood in the stool, or if symptoms persist beyond 3 days 1.

In contrast to the older study from 1990, which discussed the importance of oral rehydration therapy (ORT) in children 2, the more recent guidelines from 2017 provide a comprehensive approach to the diagnosis and management of infectious diarrhea, including viral gastroenteritis, and emphasize the importance of prevention and treatment strategies to reduce the burden of the disease 1.

From the FDA Drug Label

Dehydration Fluid and electrolyte depletion often occur in patients who have diarrhea In such cases, administration of appropriate fluid and electrolytes is very important. The use of loperamide hydrochloride does not preclude the need for appropriate fluid and electrolyte therapy Treatment of diarrhea with loperamide hydrochloride is only symptomatic. Whenever an underlying etiology can be determined, specific treatment should be given when appropriate (or when indicated).

The diagnosis of viral gastroenteritis is not directly addressed in the label, but the treatment of diarrhea (a symptom of viral gastroenteritis) with loperamide hydrochloride is symptomatic.

• Fluid and electrolyte therapy is important in patients with diarrhea.
• Loperamide hydrochloride may be used to treat diarrhea, but it does not replace the need for fluid and electrolyte therapy.
• The label recommends determining the underlying etiology of diarrhea and providing specific treatment when appropriate. 3

From the Research

Diagnosis of Viral Gastroenteritis

• The diagnosis of viral gastroenteritis is typically based on clinical symptoms, such as vomiting, diarrhea, and dehydration 4, 5, 6, 7, 8.
• Microbial studies are not needed for patients with mild symptoms that resolve within a week, but longer-lasting or more severe symptoms warrant microbial studies 6.
• Recent antibiotic exposure should prompt testing for Clostridioides difficile, and multiplex antimicrobial testing is preferred over stool cultures and microscopic stool examinations 6.

Treatment of Viral Gastroenteritis

• Oral rehydration therapy (ORT) is the main treatment for viral gastroenteritis, and is as effective as intravenous therapy in treating mild to moderate dehydration 4, 5, 7.
• Antiemetics, such as ondansetron, can be used to facilitate ORT and decrease the need for intravenous fluids and hospitalization 4, 7, 8.
• Antimicrobial therapy is indicated for C difficile infections, travel-related diarrhea, other bacterial infections with severe symptoms, and parasitic infections 6.
• Patients with mild or moderate symptoms can be treated with oral hydration, while those with more severe illness may require nasogastric or intravenous hydration 6.
• Antiemetic, antimotility, and/or antisecretory drugs can be used for symptom control in patients with viral gastroenteritis 6.