Laxative (oral) use during pelvic radiotherapy

You have been asked to take some regular laxatives before having a CT planning scan and during the first part of your radiotherapy treatment.

The position of the organs in your pelvis can change depending on how full your rectum is. The rectum is the lower part of your bowel. Keeping the rectum empty helps us plan and deliver your radiotherapy more accurately and may reduce side effects.

What to take

Take the following on the 2 evenings before your CT planning scan:
Senna 7.5 mg tablets: take 2 tablets each evening

Docusate sodium 100 mg capsules: take 2 capsules each evening

After your CT planning scan, stop the laxatives.

Restart the same laxatives 2 days before your first radiotherapy treatment.

Continue them for the first 2 weeks of radiotherapy unless your radiographer or doctor advises you to reduce or stop them.

Getting your laxatives

Senna is also called sennosides. Docusate sodium may be sold as DulcoEase, Dioctyl, or as a generic docusate sodium preparation.

Both medicines are available without a prescription from pharmacies, many supermarkets, and online retailers.

If you have not received your laxatives 3 days before your CT planning scan, please buy them over the counter. Do not wait for a new prescription if this may delay starting them.

Ask a pharmacist for help if you are not sure which product to buy. Show them this leaflet.

During treatment

It is very likely that your laxative dose will need to be reduced during treatment. Your treatment radiographers or doctor will advise you when and how to do this,

If you develop diarrhoea, meaning liquid faeces, stop the laxatives, drink more fluids, and tell your treatment radiographers at your next visit.

Mucus, slime, or small hard pellet like stools are not diarrhoea. If this happens, continue taking the laxatives unless your radiographer or doctor tells you otherwise.

If you are unable to open your bowels, ask your treatment radiographer for advice at your next visit.

Do not take extra laxatives unless advised by your radiographer, doctor, nurse, or pharmacist.

When to ask for advice before taking laxatives

Please contact your specialist radiographer or ask a pharmacist before taking these laxatives if you:

• Have severe abdominal pain
• Are vomiting
• Have been told you may have a bowel blockage
• Have been told not to take stimulant laxatives or stool softeners
• Have had an allergic reaction to Senna, sennosides, Docusate, DulcoEase, or Dioctyl

If you have questions about your laxatives, please contact your specialist radiographer.