The main goals of treatment of viral gastroenteritis are to prevent and treat volume depletion, maintain nutrition, and reduce spread to other people. Pharmacologic therapy is rarely needed.[27]Elliott EJ. Acute gastroenteritis in children. BMJ. 2007 Jan 6;334(7583):35-40.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1764079
http://www.ncbi.nlm.nih.gov/pubmed/17204802?tool=bestpractice.com
Rehydration
It is important to assess hydration status because it determines the immediate management.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Patients with profuse diarrhea and frequent vomiting, and patients with comorbidities or older age, are especially at risk for volume depletion.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Treatment is based primarily on replacing fluids and electrolytes as directed by the estimated degree of volume depletion.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Oral or enteral rehydration therapy is recommended for preventing and treating early volume depletion, and continued replacement for ongoing losses.
Oral rehydration solution
Oral rehydration solution is recommended for people with acute diarrhea from any cause. It is also recommended for people with mild to moderate dehydration associated with vomiting or severe diarrhea.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Patients with abdominal ileus should not be rehydrated orally.
Oral rehydration solution is preferable to other clear fluids. Highly sugared fluids and fluids very low in sodium may exacerbate diarrhea.[28]King CK, Glass R, Bresee JS, et al. Managing acute gastroenteritis among children: oral rehydration, maintenance, and nutritional therapy. MMWR Recomm Rep. 2003 Nov 21;52(RR-16):1-16.
https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5216a1.htm
http://www.ncbi.nlm.nih.gov/pubmed/14627948?tool=bestpractice.com
[29]Farthing M, Salam MA, Lindberg G, et al. Acute diarrhea in adults and children: a global perspective. J Clin Gastroenterol. 2013 Jan;47(1):12-20.
http://www.ncbi.nlm.nih.gov/pubmed/23222211?tool=bestpractice.com
One Cochrane review found that polymer-based oral rehydration solution (ORS) was more effective for treating acute watery diarrhea compared with glucose-based ORS.[30]Gregorio GV, Gonzales ML, Dans LF, Martinez EG. Polymer-based oral rehydration solution for treating acute watery diarrhoea. Cochrane Database Syst Rev. 2016 Dec 13;(12):CD006519.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006519.pub3/abstract
http://www.ncbi.nlm.nih.gov/pubmed/27959472?tool=bestpractice.com
Volume depletion and hypokalemia
Shock, severe volume depletion, and decreased consciousness require hospitalization and intravenous fluid resuscitation.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Approximate fluid loss should be replaced in <3 hours, followed by maintenance fluid replacement for ongoing losses. Take care not to replete patients with hypernatremia or hyponatremia too quickly, as this can lead to complications, such as osmotic demyelination syndrome.[31]Miller NE, Rushlow D, Stacey SK. Diagnosis and management of sodium disorders: hyponatremia and hypernatremia. Am Fam Physician. 2023 Nov;108(5):476-86.
http://www.ncbi.nlm.nih.gov/pubmed/37983699?tool=bestpractice.com
Volume depletion assessment should be repeated periodically and rate of fluid therapy modified based on signs of volume depletion.
Patients with severe volume depletion, particularly those with altered mental state, should be rehydrated with isotonic crystalloids, such as normal saline (0.9% sodium chloride), Ringer’s lactate, or Plasma-Lyte®.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Evidence from two large randomized controlled trials (RCTs) suggests there is no difference between normal saline and a balanced crystalloid for critically ill patients in mortality at 90 days, although results from two meta-analyses including these RCTs point to a possible small benefit of balanced solutions compared with normal saline.[32]Finfer S, Micallef S, Hammond N, et al. Balanced multielectrolyte solution versus saline in critically ill adults. N Engl J Med. 2022 Mar 3;386(9):815-26.
https://www.nejm.org/doi/10.1056/NEJMoa2114464?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
http://www.ncbi.nlm.nih.gov/pubmed/35041780?tool=bestpractice.com
[33]Zampieri FG, Machado FR, Biondi RS, et al. Effect of intravenous fluid treatment with a balanced solution vs 0.9% saline solution on mortality in critically ill patients: The BaSICS Randomized Clinical Trial. JAMA. 2021 Aug 10;326(9):1-12.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8356144
http://www.ncbi.nlm.nih.gov/pubmed/34375394?tool=bestpractice.com
[34]Hammond NE, Zampieri FG, Di Tanna GL, et al. Balanced crystalloids versus saline in critically ill adults - a systematic review with meta-analysis. NEJM Evid. 2022 Feb;1(2):EVIDoa2100010.
https://evidence.nejm.org/doi/10.1056/EVIDoa2100010?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
http://www.ncbi.nlm.nih.gov/pubmed/38319180?tool=bestpractice.com
[35]Zampieri FG, Cavalcanti AB, Di Tanna GL, et al. Balanced crystalloids versus saline for critically ill patients (BEST-Living): a systematic review and individual patient data meta-analysis. Lancet Respir Med. 2024 Mar;12(3):237-46.
http://www.ncbi.nlm.nih.gov/pubmed/38043564?tool=bestpractice.com
If there is severe hypokalemia, consider giving intravenous potassium to correct potassium rapidly. If intravenous hydration is not available or it is delayed (e.g., venous access problems) and the patient is not able to tolerate oral fluids, a central line can be placed. Nasogastric administration of oral rehydration solution may also be considered as an alternative.[19]Shane AL, Mody RK, Crump JA, et al. 2017 Infectious Diseases Society of America clinical practice guidelines for the diagnosis and management of infectious diarrhea. Clin Infect Dis. 2017 Nov 29;65(12):e45-80.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5850553
http://www.ncbi.nlm.nih.gov/pubmed/29053792?tool=bestpractice.com
Rehydration is usually achieved in 4 to 6 hours via any route. Appropriate diet should be continued as tolerated for all patients.
Other agents
The mainstay of treatment is rehydration. Routine use of antibiotics is not recommended and may even cause harm. Although not usually required, antidiarrheal agents may be used in adults for symptomatic relief of watery diarrhea. They may be considered, for example, as a specific strategy for short-term symptom management if a patient has to travel. However, avoid antidiarrheal agents in patients with bloody diarrhea (which may indicate a bacterial cause) or where an inflammatory cause is suspected, as it may prolong the infection.[25]Riddle MS, DuPont HL, Connor BA. ACG clinical guideline: diagnosis, treatment, and prevention of acute diarrheal infections in adults. Am J Gastroenterol. 2016 May;111(5):602-22.
http://www.ncbi.nlm.nih.gov/pubmed/27068718?tool=bestpractice.com
[36]Meisenheimer ES MD, MBA, Epstein C DO, Thiel D MD, MPH. Acute diarrhea in adults. Am Fam Physician. 2022 Jul;106(1):72-80.
https://www.aafp.org/pubs/afp/issues/2022/0700/acute-diarrhea.html
http://www.ncbi.nlm.nih.gov/pubmed/35839362?tool=bestpractice.com
Likewise, antiemetics are not recommended unless the patient has intractable vomiting.