Antidiarrheal Medication: Everything You Need to Know

Antidiarrheal drugs are administered as symptomatic treatment, since diarrhea is a symptom, not a disease in itself. In any case, there are general guidelines in the treatment of diarrhea.
Antidiarrheal Medication: Everything You Need to Know
Mariel Mendoza

Reviewed and approved by the doctor Mariel Mendoza.

Written by Editorial Team

Last update: 24 November, 2022

Antidiarrheal medication is prescribed, as its name suggests, for the treatment of diarrhea. Depending on the cause of the disease and the symptoms it produces, the exact product will vary.

Diarrhea is a very common reason for going to the doctor’s, both in primary care and directly at the pharmacy. In order to better understand how these drugs work, it’s essential to have a better understanding of the digestive disorder they’re being prescribed for.

What is diarrhea and why does it occur?

Diarrhea is a condition that affects the digestive system, specifically fecal transit, causing it to speed up and making stools more frequent and of poor consistency.

The causes of this condition are usually imbalances between the substances that are absorbed and secreted in the intestine. However, diarrhea is also a very common adverse reaction to many drugs.

Infections caused by certain pathogenic microorganisms can also produce this symptom. On the other hand, it’s important to know that diarrhea, in general terms, can be classified into two types: acute diarrhea and chronic diarrhea.

As for the former, it affects more than one billion people every year in the world’s population, especially in developing countries. It’s usually triggered by an infection and doesn’t usually require drug treatment, and goes away on its own.

Chronic diarrhea occurs when diarrhea persists after two to three weeks of treatment. This term is used when a patient suffers from this disease for more than two months, and can be due to different causes, although most commonly it’s due to gastrointestinal disease.

A man on the toilet
Diarrhea is a digestive symptom that can occur due to an infection or as an adverse reaction to certain medications.

What antidiarrheal medication is available?

Antidiarrheal medication is administered as a symptomatic treatment, as diarrhea is a symptom, not a disease in itself. In any case, there are general guidelines for the treatment of diarrhea:

  • Rehydration: When a patient suffers diarrhea, they lose a lot of water and electrolytes that are important to replace.
  • Administration of prebiotics: It’s very common for the intestinal microbiota to be affected during diarrhea.
  • Antidiarrheal medication: However, these aren’t always necessary.

The pharmacological treatment of diarrhea will be varied according to the intensity, duration, and cause of the diarrhea, and is aimed at reducing or suppressing the symptoms of diarrhea. Here are some of the most commonly used antidiarrheals.

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Activated charcoal or albumin tannate

These drugs have a localized action. Specifically, they act on the inner wall of the large intestine. They’re very safe options, with hardly any adverse effects according to the studies carried out.

In general, they have little effect on reducing stool quantity and stool frequency, but they do affect stool consistency.


This antidiarrheal affects the anal sphincter tone and improves fecal continence. It is, therefore, a drug that affects gastrointestinal motility, slowing it down. This effect causes the reabsorption of water and electrolytes in the intestine to be enhanced, resulting in an increase in stool consistency.

A doctor writing.
Antidiarrheal medications are prescribed only in certain cases. The physician may suggest one option or another, depending on the causes and severity of the diarrhea.


These drugs are not recommended as first-choice treatment. The reason for this is that almost all diarrhea is caused by a viral, not a bacterial, infection.

However, if the diarrhea is caused by a bacterial infection, its recommended to perform an antibiogram to get to know the sensitivity of the pathogen and thus be able to administer an appropriate antibiotic.

An antibiogram is a technique performed in the laboratory, which consists of culturing an infected sample and treating it with different antibiotics to find out which one is more effective.


Fortunately, nowadays we have a wide range of antidiarrheals that ensure that diarrhea isn’t one of the main causes of death in developed countries.

To know which antidiarrheal medication to use, it’s essential to know what has triggered this unpleasant condition. We recommend that you consult your doctor or pharmacist if you have any questions about this type of medication.

All cited sources were thoroughly reviewed by our team to ensure their quality, reliability, currency, and validity. The bibliography of this article was considered reliable and of academic or scientific accuracy.

  • Barreiro de Acosta, M., & Domnguez Muoz, J. E. (2004). Tratamiento de la diarrea. Medicine – Programa de Formaci?N M?Dica Continuada Acreditado.
  • del Arco, RT Sánchez, JM Machín Lázaro, and P. Checa Díaz. “Protocolo diagnóstico y terapéutico de la diarrea aguda.” Medicine-Programa de Formación Médica Continuada Acreditado 12.87 (2019): 5135-5139.
  • Di John, D. “Tratamiento farmacológico de la diarrea aguda.” ARS MEDICA Revista de Ciencias Médicas 17.2 (2017): 59-64.
  • Inhibición del tránsito intestinal por el extracto metanólico de las hojas de Annona muricata L (guanábana) en ratones. (2011). Ciencia e Investigación.
  • Román, E., María, Y., & Cilleruelo, L. (2003). Ensayos clínicos y práctica clínica Racecadotrilo en la gastroenteritis aguda infantil. An Pediatr Contin.

This text is provided for informational purposes only and does not replace consultation with a professional. If in doubt, consult your specialist.