This advice is sourced from Dr Ros Taylor a senior palliative physician
These are some questions I am often asked about constipation and medication.
Which medicines cause constipation?
Many painkillers especially morphine and related medicines such as codeine, tramadol, fentanyl and oxycodone.
Nerve pain medicines such as pregabalin, gabapentin and amitriptyline.
Muscle relaxants such as buscopan and some anti-sickness drugs like cyclizine and ondansetron.
How do these medicines cause constipation?
The main reason that medicines cause constipation is that they slow down bowel transit time (the amount of time it takes for food to pass down through the digestive system).
The longer bowel contents are in the bowel, the drier they get as water is absorbed out of the stools back into the body.
What are the best treatments for constipation caused by medication?
You need treatments to speed up the bowel (e.g. senna or picosulfate) whilst taking medication that slows the bowel down.
You may need something to soften the stools (e.g. laxido, movicol or docusate).
If you have always had a medication for constipation that works well for you this is the one to use initially.
What are the other approaches that can help?
Remember that drinking enough fluid is crucial for softening stools.
Eating foods which contain fibre also helps (e.g. fruit, vegetables, wholegrains).
If the stool is really hard to push out, then gylcerine suppositories may help soften the stool and make it easier to pass.
Good toilet posture can be very helpful. This webpage from Macmillan explains how sitting in the right position on the toilet can help.
If constipation improves can I stop taking laxatives?
It is recommended to always use regular laxatives whilst taking regular medication, particularly strong painkillers.