How to take Loperamide (Imodium®)
Date issued: April 2023
For review: April 2025
Ref: B-332/AC/Medicine/How to take Loperamide (Imodium) v3
PDF: How to take Loperamide (Imodium) final April 2023 v3.pdf [pdf] 159KB
Instructions for patients seen in the Pelvic Floor Clinic
What is Loperamide?
Loperamide (also known as Imodium) is an anti-diarrhoeal medicine. These drugs are designed to thicken your poo and so to reduce diarrhoea. It will also firm up slightly soft poo.
What is it used for?
Loperamide is used for a range of problems including travellers’ diarrhoea. However, our main use of it in the Pelvic Floor clinic is to improve bowel function and control (continence).
How does it improve bowel control?
Many people who have problems with bowel control (incontinence) have loose bowel motions or find that their problem is worse if their poo is soft. Loperamide works by slowing down the passage of food through the gut. Your body can then draw in more water from your intestines, making the poo thicker and firmer. This makes it easier to hold on when you have the urge to pass a poo. Loperamide has also been shown to have other effects including tightening the sphincter muscle of the bottom and in altering reflexes, ‘nerve messages’ sent between the bowel and the sphincter muscle.
How should I use the Loperamide?
A suggested starting dose will be discussed with you. It is usual to start with one capsule/tablet (2mgs), swallowed whole once a day but some people may require a larger dose. People can vary in their response to Loperamide. It sometimes needs some experimentation to find the dose that will control the consistency of the poo without constipating you. The more you take, the firmer your poo should become and if you take more than you need you may feel constipated. If you do not take enough your poo will remain loose or soft. It is usual to start on a low dose and build up slowly over a few days so that you can judge how your body is responding. You should not take more than eight tablets (16mg) per day unless instructed otherwise by your doctor.
What if I only need a tiny amount?
Sometimes patients find that they only need to take as little as one tablet (2mg) every other day, otherwise you may become constipated with using it regularly. If you find you require only a very low dose, you may find Loperamide tablets more convenient as with a tablet cutter, you can cut it in half to give you 1mg or into a quarter to give 0.5mg.
Amount you take |
Actual dose of Loperamide |
1 capsule/tablet |
2 milligrams |
½ tablet |
1 milligram |
¼ tablet |
0.5 milligram |
It is best to take Loperamide half an hour before a meal, particularly if eating is a trigger for you to have to have your bowels open following. This will help to slow down the gut activity that is stimulated by eating. Most people find that the bowel is most active in the morning and so Loperamide will help if taken before breakfast or even the night before.
The medicine starts to work within half an hour of taking it and is effective for 8-12 hours. This means that doses taken after lunch are not likely to help much if your problems are in the morning. However, a dose last thing at night may help with early morning frequency. If you prefer to take with food or after you have eaten, this is perfectly acceptable.
Most people take Loperamide on a daily basis but it is equally as useful taken when required if your stools are loose, or 30 minutes before you go out, however an established routine with the medication, generally helps with having a predictable bowel routine.
Loperamide can be used with glycerine suppositories to help prevent leakage of stool. The Loperamide makes the stool firmer and the glycerine suppositories empty out the back passage so that there is no poo present to cause leakage. Most people need to use the Loperamide and suppositories daily to achieve this. You may need to experiment with the dosage and timing to fit in with your life style.
Loperamide can also be used with Fybogel® to achieve a firm bulky poo. This is easier for the back passage muscles to control and so can reduce the chances of leakage. Again you will need to experiment with the dosage and timing of both medications to gain the correct stool consistency.
Is Loperamide safe?
Loperamide is widely used by patients with incontinence but should be used only on medical advice. It can result in constipation if too high a dose is taken. Other common side effects include feeling dizzy, sick, headaches or farting (wind). You should always read the label and a list of the interactions and safety advice will be found in the drug information leaflet within the box. Loperamide is not usually recommended in pregnancy.
What are the alternatives?
There are other tablets that have a similar side effect on the bowel, these include codeine phosphate but they have more side effects and so are not tried as first line.
Any further questions?
If you have any questions you can contact the Pelvic Floor Nurse Specialist, Monday to Friday, 9-4pm on 01752-431166. Outside of these hours you may leave a message on this number. We will aim to answer your query within 48hours. Alternatively you can email your query to ann.cornelius@nhs.net