Prevent dehydration with oral rehydration solutions (e.g., Pedialyte) and consider bismuth subsalicylate (Pepto Bismol) to reduce stool frequency and symptoms. Loperamide or loperamide/simethicone combinations can also provide symptom relief but should not be used for more than 48 hours without medical evaluation. Seek medical attention if you are immunocompromised, have diarrhea for more than 7 days, or notice blood in your stool.
January 15, 2025

Diarrhea: Fastest Doctor-Recommended Ways to Get Better

Evidence-Based Over-The-Counter Guide

William Shen

William Shen

Co-founder & CPO

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This guide is based on the 2016 American College of Gastroenterology guidelines that doctors follow. 

Acute (<7 days) diarrhea that is non-bloody and non-fatty can be managed with non-prescription medication for relief and oral rehydration solution to prevent dehydration from fluid loss.

Ask a doctor and do not use this guide if you:

  • Are immunocompromised

  • Have diarrhea for more than 7 days

  • Have blood in your stool

Doctor’s first choice:

  • Oral rehydration solutions (ORS): Prevent dehydration with balanced glucose-electrolyte solutions such as Pedialyte Electrolyte Powder in water. Diarrhea depletes electrolytes so drinking water alone is not sufficient and is also not absorbed as efficiently. Drink at least 1 cup of Pedialyte or equivalent solution every time you have a loose bowel movement.

  • Bismuth subsalicylate: Can reduce stool frequency by ∼ 40% to help you resume normal activities. More safe than loperamide if you have fever. Stool and tongue may temporarily turn black. The recommended dose of Pepto Bismol Liquid (FDA M008) for therapy of acute diarrhea is 30 ml (525 mg) of liquid formulation or two tablets (263 mg per tablet) chewed well each 30–60 min not to exceed eight doses in 24 hr.

  • Maintain nutrition: As soon as possible, try to resume normal eating. Starting with a BRAT diet (bananas, rice, applesauce, and toast) and avoiding dairy is commonly doctor-recommended.

Additional options: 

  • Loperamide: Imodium Diarrhea Relief Caplets (FDA N021855) slow intestinal motility to alleviate symptoms of diarrhea. Dose: 4 mg orally initially, followed by 2 mg after each loose stool (max 8 mg/day). Should not be used for > 48 hours without evaluation by a doctor. Do not exceed the recommended dose as you can give yourself constipation after the diarrhea passes.

  • Loperamide/simenthicone: Acute nonspecific diarrhea and gas-related discomfort, such as from irritable bowel syndrome, is better relieved with a loperamide/simethicone combination (FDA N021855/M002) than either drug alone. Both are FDA-approved OTC medications for diarrhea and extra gas (flatulence), respectively. 

Prevention while traveling:

  • Bismuth subsalicylate: Pepto Bismol tablets (FDA M008) can be used safely for up to 2 weeks to prevent diarrhea. The over-the-counter drug provides at least 60% protection when using 2100 mg (4 tablets) per day. 

Prescription medications: 

  • Antibiotics: Prescribed for some bacterial causes of diarrhea where evidence of helpfulness exists. In some cases antibiotics can prolong or worsen diarrhea.

  • Anti-inflammatory agents: For inflammatory bowel diseases.

Citations:

Riddle MS, DuPont HL, Connor BA. ACG Clinical Guideline: Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults. Am J Gastroenterol. 2016; 111(5): p.602-622. doi: 10.1038/ajg.2016.126

Barr W, Smith A. Acute diarrhea in adults. Am Fam Physician. 2014; 89(3): p.180-189. pmid: 24506120.

What OTC evidence is reviewed?

  • For each condition, we performed a literature review to find a recent widely cited expert group guideline published in the leading specialty-specific peer-reviewed journal or top general medical journal.

  • Based on the recommendations in the publication, we identify recommended active ingredients and devices that are available over-the-counter per FDA regulations.

What evidence is prioritized?

Levels of evidence considered:

  • Tier 1 (Safe and Definitely Effective): Professional field consensus or multiple randomized controlled clinical trials showing the same conclusion. Wherever possible, we use Tier 1 evidence for "first-line" recommendations.

  • Tier 2 (Safe and Probably Effective): Individual clinical trials which may be discordant or large-scale observational experience. Tier 2 evidence may inform "first-line", "second-line", or "supplement" recommendations.

  • Tier 3 (Safe and Maybe Effective): Mechanistic plausibility without high-quality clinical evidence of efficacy but high-quality evidence of safety. Tier 3 evidence may inform "second-line" or "supplement" recommendations.

How does MDandMe select recommended products?

  • Based on the top clinical recommendation, we evaluate products containing the recommended active agent with FDA-approved dosage based on price, average customer reviews, how often it is purchased, and how quickly it will ship to home. 

  • We provide public documentation of the active ingredients in our recommendations, using all 32 FDA monographs, Prescription-to-Nonprescription (Rx-to-OTC) Switches, as well as New Drug Application (NDA) approvals.

How does MDandMe select recommended devices?

  • Based on the top clinical recommendation, we evaluate devices that are FDA-cleared or comply with other medical guidelines (if not a FDA-regulated category) by reputability, price, and average customer reviews.

  • We provide public documentation of supporting evidence for each device.  

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