How to Stop Diarrhea in Adults Fast? 5 Best OTC Medications

Khang T. Vuong, MHA
Khang T. Vuong, MHA15 Sep 2023

What Causes Diarrhea?

The World Health Organization estimates that each year, 2 billion cases of diarrhea occur, primarily instigated by infectious pathogens. About 1.9 million children under the age of five in low- and middle-income countries perish because of this condition, making diarrhea the second leading cause of death in this age group.

The pathogens contributing to the enormous burden of diarrheal diseases vary widely. A systematic analysis of the Global Burden of Diseases, Injuries and Risk Factors study showed four primary pathogens to be responsible for many diarrhea cases worldwide. 

Cause of DiarrheaPrevalenceSymptoms
Viral infections70%Watery stools, nausea, vomiting, stomach cramps, fever
Bacterial infections20%Watery stools, bloody stools, mucus in stools, stomach cramps, fever
Parasitic infections10%Watery stools, foul-smelling stools, gas, bloating, weight loss
Food allergies and intolerances5%Watery stools, bloating, gas, abdominal pain
Medications5%Watery stools, abdominal pain
Inflammatory bowel disease (IBD)2%Watery stools, bloody stools, mucus in stools, stomach cramps, fever, weight loss
Malabsorption syndromes1%Watery stools, bloating, gas, weight loss

How Long Does Diarrhea Last?

The duration of diarrhea largely depends on its cause. As per the information provided by Mayo Clinic, acute diarrhea - often a result of a bacterial or viral infection - typically lasts one to two days and disappears on its own without treatment. However, prolonged or chronic diarrhea that persists for four or more weeks may indicate a serious health problem requiring medical attention.

When Should I See a Doctor for Diarrhea?

While most cases of diarrhea resolve independently, it's crucial to consult a healthcare provider if your symptoms persist for more than a few days or are accompanied by high fever, bloody stools, severe pain, or signs of dehydration like dark urine and extreme thirst. These could point towards a more serious underlying condition. If you don't have insurance, Mira could be a great option at $45/month

Seek medical attention if you experience any of the following symptoms related to diarrhea:

  • Persistent diarrhea lasting more than 3 days.
  • Presence of fever, bloody stools, or mucus in the stools alongside diarrhea.
  • Severe abdominal pain or cramping with diarrhea.
  • Signs of dehydration, including:
    • Dry mouth
    • Decreased urination
    • Lightheadedness
  • Diarrhea in vulnerable populations, such as:
    • Infants and young children
    • Individuals with weakened immune systems (e.g., those with HIV/AIDS or cancer)
  • Diarrhea potentially caused by medications you are taking.
  • Diarrhea accompanied by any other concerning symptoms.

5 Best Over-the-counter Medications for Diarrhea Relief

Imodium, primarily containing Loperamide, is a go-to over-the-counter solution for alleviating diarrhea by moderating gut movement. Pepto-Bismol and Kaopectate both use Bismuth Subsalicylate as their key ingredient, providing relief from diarrhea and associated stomach discomfort; with the former also serving as an antacid. Maalox, formulated with Aluminium Hydroxide and Magnesium Hydroxide, stands out as an effective neutralizer for excess stomach acid, targeting heartburn and indigestion besides diarrhea. Activated Charcoal, distinct from the others, is valued for its ability to absorb toxins and bacteria causing diarrhea. 

Lastly, Oral Rehydration Solutions (ORS) are crucial in replenishing fluids and electrolytes lost due to diarrhea, preventing dehydration. All these medications offer unique benefits in addressing diarrhea and its related symptoms, but it's essential to consult a healthcare professional for appropriate use and dosage.

MedicationKey IngredientBest For
ImodiumLoperamideAlleviating diarrhea by slowing down gut movement
Pepto-BismolBismuth SubsalicylateDiarrhea, stomach discomfort, and as an antacid
KaopectateBismuth SubsalicylateDiarrhea and associated stomach discomfort
MaaloxAluminium Hydroxide and Magnesium HydroxideNeutralizing excess stomach acid, heartburn, indigestion
Activated CharcoalCharcoal (activated form)Absorbing toxins and bacteria causing diarrhea

1. Imodium (Loperamide): A Proven Solution for Diarrhea

Imodium, an over-the-counter medication, is widely recognized for its effective role in alleviating diarrhea symptoms by controlling intestinal movement. This anti-diarrheal medication works by slowing down gut performance, essentially reducing the frequency and urgency of bowel movements (WebMD). The national average cost for this medication ranges from $8 to $12 for a pack of 30 capsules. However, prices may vary depending on the location and store.

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Dosage and Precautions

Age groupInitial doseSubsequent dose
Adults and children 13 years of age and older4 mg (two capsules)2 mg (one capsule) after each loose stool
Children 2 to 5 years of age1 mg orally 3 times a day (3 mg total daily dose)1 mg only after a loose stool, not to exceed 3 mg/day
Children 6 to 8 years of age2 mg orally twice a day (4 mg total daily dose)1 mg only after a loose stool, not to exceed 4 mg/day
Children 8 to 12 years of age2 mg orally 3 times a day (6 mg total daily dose)1 mg only after a loose stool, not to exceed 6 mg/day
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2. Pepto-Bismol (Bismuth Subsalicylate): Comprehensive Relief from Stomach Discomfort

Pepto-Bismol's role as an antidiarrheal and an antacid has made it a popular choice for people suffering from diarrhea and associated stomach discomfort. Bismuth subsalicylate, the key ingredient in Pepto-Bismol, minimizes inflammation in the stomach and intestines, and bonds with harmful substances potentially triggering diarrhea (Healthline). The average cost for Pepto-Bismol typically fluctuates within a range of $5 to $10 for a bottle of 30 chewable tablets.

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3. Kaopectate (Bismuth Subsalicylate): Effective Diarrhea and Discomfort Relief

Kaopectate, a medication similar to Pepto-Bismol, contains Bismuth Subsalicylate as its main component, which is known for providing relief from diarrhea and associated stomach discomfort. Bismuth subsalicylate is particularly effective in relaxing the gastrointestinal tract by reducing inflammation and bonding with harmful substances that contribute to diarrhea ( Depending on the store and location, the average cost of Kaopectate ranges from $5 to $10 for a bottle of 8 ounces.

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4. Maalox (Aluminium Hydroxide and Magnesium Hydroxide): Neutralizer for Excess Stomach Acid

Maalox has made its mark as an effective antacid and anti-gas medication that soothes diarrhea and stomach discomfort caused by an excess of stomach acid. The combination of aluminum hydroxide and magnesium hydroxide in Maalox plays a key role in neutralizing stomach acid, thereby alleviating symptoms such as diarrhea, heartburn, and indigestion (MedlinePlus). The average cost of Maalox is around $7 for a 12-ounce bottle but can vary based on the store and location.

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Dosage and Precautions

Age groupDose
Adults and children 12 years of age and older5-15 mL (1-3 teaspoons) by mouth after each loose stool. Do not exceed 40 mL (8 teaspoons) in 24 hours.
Children 6 to 11 years of age5 mL (1 teaspoon) by mouth after each loose stool. Do not exceed 20 mL (4 teaspoons) in 24 hours.
Children 2 to 5 years of age2.5 mL (1/2 teaspoon) by mouth after each loose stool. Do not exceed 10 mL (2 teaspoons) in 24 hours.
Children under 2 years of ageAsk a doctor.
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5. Activated Charcoal: A Solution to Toxin-Induced Diarrhea

Activated charcoal possesses the ability to absorb toxins and bacteria causing diarrhea, thus ameliorating the symptoms. When grappling with digestive issues such as diarrhea, activated charcoal can come in handy due to its toxin-attracting properties. According to Healthline, the porous surface of activated charcoal draws in and traps harmful toxins and bacteria. What follows is their elimination from the body through excretion, thereby resulting in a decrease in diarrhea symptoms (source: Healthline).

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Do Natural Remedies Work for Diarrhea Relief?

When confronted with a bout of diarrhea, there are several home remedies that may help alleviate symptoms and restore balance in your digestive system. According to Harvard Health Publishing, one tried-and-true method is the BRAT diet, which is an acronym for Bananas, Rice, Applesauce, and Toast. These bland foods are gentle on the stomach, low in fiber, and can help solidify stools.

Another essential strategy is keeping yourself well-hydrated. Diarrhea often leads to loss of fluids and electrolytes, which can result in dehydration. Consuming plenty of clear liquids, including water, broths, and fruit juices minus the pulp can aid in keeping you hydrated.

Probiotics, often referred to as 'good bacteria,' can also play a role in tackling diarrhea, particularly when it's caused by antibiotic usage. Foods like yogurt and kefir are naturally rich in probiotics. A study published in the Journal of Clinical Gastroenterology found that probiotics could reduce antibiotic-associated diarrhea by about 60%.

Are There Any Side Effects from Using Over-The-Counter Diarrhea Medications?

While over-the-counter (OTC) diarrhea medications such as loperamide (Imodium) and bismuth subsalicylate (Pepto-Bismol) can provide quick relief, their use may also bring potential side effects. Common side effects include dizziness, constipation, and abdominal pain (source: MedlinePlus). It's essential to follow the package instruction and not use these drugs excessively to minimize the potential for adverse effects.

7 Misconceptions About Diarrhea

Diarrhea is a common condition that most people will experience at various points in their life. Due to its prevalence, there are many misconceptions surrounding it. Here are some of those misconceptions, along with the evidence-based clarifications:

Misconception 1: Diarrhea is just an inconvenience and isn't serious.

  • Fact: While many cases of diarrhea are self-limiting and may not pose significant health risks, severe or prolonged diarrhea can lead to dehydration and nutrient malabsorption. In many parts of the world, particularly where access to clean water and sanitation is limited, diarrhea is a leading cause of childhood mortality.

Misconception 2: All diarrhea is caused by infections.

  • Fact: While many cases of diarrhea are indeed infectious in origin (caused by bacteria, viruses, or parasites), there are many other potential causes, including certain medications, food intolerances, and conditions such as irritable bowel syndrome or inflammatory bowel disease.

Misconception 3: Antibiotics are needed to treat all cases of diarrhea.

  • Fact: Not all diarrheal illnesses require antibiotics. In fact, many are caused by viruses, against which antibiotics are ineffective. Overuse of antibiotics can contribute to antibiotic resistance and can also disrupt the normal gut flora, leading to other problems, such as Clostridioides difficile infection.

Misconception 4: Boiled rice water is an effective treatment for diarrhea.

  • Fact: While boiled rice water might be soothing and can provide some basic nutrition during diarrheal illness, the World Health Organization (WHO) recommends oral rehydration solutions (ORS) as the primary treatment for dehydration caused by diarrhea. ORS contains a precise balance of salts and sugars to promote rehydration.

Misconception 5: Only dirty or contaminated food causes diarrhea.

  • Fact: While contaminated food and water are common causes of diarrhea, many other factors can lead to the condition. This includes "clean" foods that might not agree with someone's digestive system, certain medications, or even stress.

Misconception 6: Diarrhea flushes toxins from the body, so it's good to let it run its course.

  • Fact: While the body can indeed use diarrhea as a way to eliminate certain pathogens or toxins, severe or prolonged diarrhea can be harmful due to dehydration and the loss of essential nutrients and electrolytes. It's essential to manage diarrhea and ensure proper hydration.

Misconception 7: Only travelers get "traveler's diarrhea."

  • Fact: While "traveler's diarrhea" is a common condition affecting tourists, especially in certain parts of the world, local residents can also get sick from the same pathogens. The difference is often due to the immunity that locals might build up over time.


Diarrhea, while uncomfortable and disruptive, is often a temporary ailment that can be treated with over-the-counter medications and home remedies. However, if symptoms persist or are accompanied by other severe symptoms like dehydration or blood in the stool, it's essential to consult a healthcare professional promptly. Always make sure to adhere strictly to medication dosages and consult with a pharmacist or doctor if unsure.

Khang T. Vuong, MHA

Khang T. Vuong received his Master of Healthcare Administration from the Milken Institute School of Public Health at the George Washington University. He was named Forbes Healthcare 2021 30 under 30. Vuong spoke at Stanford Medicine X, HIMSS conference, and served as a Fellow at the Bon Secours Health System.