What can diarrhoea be a symptom of?

Diarrhoea is a common digestive disorder that can be caused by several factors such as infections, food poisoning, changes in diet, or medications. It can cause abdominal cramps, frequent and loose bowel movements, and dehydration. 

While severe cases of diarrhoea may require medical attention, mild cases can be treated with over-the-counter medications, such as tablets for treating diarrhoea. 

It is important to take a closer look at how these tablets work and what you need to know before using them.

How do diarrhoea tablets work to relieve symptoms?

Diarrhoea medications work by either slowing down the muscles of the intestines or increasing the absorption of water in the intestines. There are 2 main types of diarrhoea tablets: antimotility agents and osmotic agents.

Antimotility agents

Antimotility agents, also known as antimuscarinic or anticholinergic agents, work by slowing down the contractions of the muscles in the intestines.


This reduces the frequency and urgency of bowel movements and helps to solidify stools. Examples of antimuscarinic agents include loperamide (Imodium) and diphenoxylate (Lomotil).

Osmotic agents

Osmotic agents work by drawing water into the intestines and increasing the bulk of the stool. This helps to soften the stools and relieve diarrhoea. 

Examples of osmotic agents include kaolin and pectin (Kaopectate), bismuth subsalicylate (Pepto-Bismol), and magnesium hydroxide (Milk of Magnesia).

When should you use diarrhoea tablets?

Diarrhoea medications can be used to relieve the symptoms of mild diarrhoea. They are not recommended for severe cases of diarrhoea, as they can prolong the illness and delay recovery. If you have severe diarrhoea, it is best to see a doctor for proper diagnosis and treatment.

If you have mild diarrhoea and are otherwise healthy, it is generally safe to use over-the-counter tablets for diarrhoea. However, there are certain cases where it is not recommended to use these tablets. For example, if you have a fever, bloody stools, or signs of dehydration, it is best to seek medical attention as these could be signs of a more serious underlying condition.

It is also important to note that tablets for diarrhoea should not be used as a long-term solution for chronic diarrhoea. If you have persistent diarrhoea, it is best to consult a doctor specialising in gastroenterology for proper evaluation and treatment.

What should you consider before using diarrhoea tablets?

Before using diarrhoea medication, it is important to consider the following:

Active ingredients: Different tablets for diarrhoea contain different active ingredients, and each may have different side effects and interactions with other medications. It is important to carefully read the label and inquire your doctor or pharmacist about any questions or concerns you may have regarding the active ingredient in the tablet.

Dosage: The recommended dosage for diarrhoea medication varies depending on the active ingredient and the product. It is important to follow the instructions on the label and not exceed the recommended dose. Overuse of tablets for diarrhoea can lead to adverse side effects and may even be dangerous.

Interactions with other medications: Some tablets for diarrhoea can interact with other medications, such as antibiotics, antidepressants, and pain relievers. If you are taking any other medications, it is important to check with your doctor or pharmacist to see if they interact with the diarrhoea tablet you are considering.

Pregnancy and breastfeeding: If you are pregnant or breastfeeding, it is important to talk to your doctor before using any over-the-counter medications, including tablets for diarrhoea. Some active ingredients in diarrhoea medications can be harmful to the developing foetus or may pass into breast milk and affect the nursing baby.

Allergies and sensitivities: If you have any allergies or sensitivities to the active ingredient or any other ingredients in the diarrhoea tablet, it is important to check the label and consult your doctor or pharmacist before using the product.

What are the side effects of diarrhoea tablets?

Like any medication, tablets for treating diarrhoea can cause side effects. Common side effects of antimuscarinic agents include the following:

  • Constipation 

  • Bloating 

  • Nausea 

  • Abdominal cramps 

  • Gas 

  • Cramping 

If you experience any severe or persistent side effects, it is best to stop using the medication and promptly seek medical attention.

Consult a gastrointestinal specialist

Dr. Suhirdan Vivekanandarajah is a Sydney-based gastroenterologist and hepatologist. His extensive training has enabled him to help his patients work towards better digestive health.

To find out how you can improve your digestive health, schedule a consultation with him today.