Medication Information Leaflet

What are these medications for?

Anti-diarrhoeals help to relieve diarrhoea. They may include medications such as:

  • Activated charcoal
  • Kaolin
  • Dioctahedral smectite
  • Lactobacillus Acidophilus
  • Loperamide
  • Diphenoxylate

Activated charcoal, kaolin and dioctahedral smectite work by binding to the toxins in your stomach. Lactobacillus Acidophilus has been suggested to work by protecting the gut lining and maintaining healthy bacteria in your stomach. Loperamide and diphenoxylate work by slowing your stomach  movement. They may be found in liquid, powder, capsule or tablet form. Oral rehydration salts may also be used to replace water and salts lost through diarrhoea.

How should I take these medications?

  • Take a dose when necessary to relieve symptoms of diarrhoea.
  • Take these medications as recommended by your healthcare professional. Consult your healthcare professional if you are not sure how to take these medications correctly.
  • These medications may be taken before or after food.
  • If your symptoms persist or worsen after 1 week of taking these medications, please speak to your healthcare professional.

What should I do if I forget to take these medications?

Anti-diarrhoeals may be taken when required for a short period of time. This means you no longer have to take them if you do not have any more symptoms. If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue normally. Do not take two doses or extra medication to make up for the missed dose.

What precautions should I take when taking these medications?

Inform your healthcare professional if:

  • You are allergic to anti-diarrhoeals, or any other ingredients used in these medications.
  • You are pregnant, planning to become pregnant or breastfeeding.
  • You are taking any other medications, including supplements, traditional medications and herbal remedies.
  • You have any medical conditions.

If you take more than the recommended dose, please seek medical advice immediately.

What are some common side effects of these medications?

Anti-diarrhoeals may cause the following side effects:

  • Activated charcoal may cause black stools.
  • Some anti-diarrheals may cause drowsiness, dry mouth, dizziness and constipation.

These side effects are usually mild and go away after some time. However, if the symptoms are bothersome, do not go away or become worse, stop these medications and consult your healthcare professional.

What are some rare but serious side effects that I need to see a doctor immediately?

The symptoms of a drug allergy include one or more of the following: 

  • Swollen face/eyes/lips/tongue
  • Difficulty in breathing
  • Itchy skin rashes over your whole body

If you experience any of these symptoms, you should stop these medications and see your doctor immediately.

Signs that your condition may require further medical attention include:

  • Persistent vomiting
  • Your diarrhoea lasts for more than one week even after self-medicating
  • You have symptoms of dehydration such as dry lips, extreme thirst, passing urine less often, dark-colored urine and dizziness 
  • Very bad pain in your stomach or anus area
  • Blood and/or pus in the stools or black and sticky stools
  • Fever
  • You have just returned from an area where there has been recent cases of a gut infection known as cholera

If you experience any of these symptoms, you should stop these medications and see your doctor immediately.

What food or medication should I avoid when I take these medications?

Activated charcoal, kaolin and dioctahedral smectite may reduce the absorption of other medications. They must be taken apart from other medications by two hours. 

As other anti-diarrhoeals may interact with other medications, let your healthcare professional know if you are taking, or planning to take any other herbal products, supplements or medications.

How should I store these medications?

Store in a cool and dry place, away from direct sunlight. Keep these medications away from children. 

How do I throw these medications away safely?

Pack these medications into a black trash bag and seal it tightly before throwing it into the rubbish chute or bin.


This article is jointly developed by members of the National Medication Information workgroup. The workgroup consists of cluster partners (National Healthcare Group, National University Health System and SingHealth), community pharmacies (Guardian, Unity and Watsons) and Pharmaceutical Society of Singapore. The content does not reflect drug availability and supply information in pharmacies and healthcare institutions. You are advised to check with the respective institutions for such information.

The information above is solely for informational purposes only and is not intended as a substitute for the advice provided by your physician, pharmacist or other healthcare professional. You should not use the information for diagnosing or treating a health problem or disease, or prescribing any medicine or other treatment. Always speak with your physician, pharmacist or other healthcare professional before taking any medicine or supplement, or adopting any treatment for a health problem. Under no circumstances will the National Medication Information workgroup be liable to any person for damages of any nature arising in any way from the use of such information.

Last updated on September 2023

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