• People taking opioid analgesics should also take a stimulant laxative and a softening laxative.

In depth

• Confirm that the person is constipated and exclude or manage bowel obstruction, anal fissure, painful haemorrhoids and local tumour.
• Begin treatment by relieving any faecal loading/impaction.
• Encourage the person to increase their physical activity and their fluid and dietary fibre intake if appropriate.
• Ensure adequate privacy and sufficient help to get to the toilet.
• Start treatment with a combination of a stimulant plus a softening laxative.
• If colic is a problem, use a softening laxative for a few days, and then add in the stimulant.
• A stimulant laxative alone may be sufficient if the rectum is full of soft faeces.
• Titrate the dose every few days to achieve comfortable defecation.
• It may be necessary to exceed the licenced dose and frequency.
• Adjust the laxative dose in line with the opioid dose.

In depth

• Start treatment with a combination of a stimulant and softening laxative.
• When the response to initial treatment is insufficient or not fast enough:
• For high faecal impaction/loading, consider a bowel washout with an oral macrogol.
• For low faecal impaction/loading (i.e. stool is in the rectum), consider:
• Using a suppository: bisacodyl for soft stools, glycerol alone or glycerol plus bisacodyl for hard stools.
• Using a mini-enema: docusate or sodium citrate.
• If the response is still insufficient:
• Consider using a sodium phosphate enema, or an arachis oil retention enema, placed high if the rectum is empty but the colon is full.
• For hard faeces it can be helpful to give the arachis oil enema overnight before giving a sodium phosphate (large volume) or sodium citrate (small volume) enema the next day.
• Enemas may need to be repeated several times to clear hard impacted faeces.
• If none of these measures provide relief, then consider manual evacuation.

In depth

• Check that the dose of stimulant and softening laxative has been adequately titrated.
• Adjust the dose of stimulant to produce defecation without colic.
• Adjust the dose of softener to produce a comfortable stool.
• Higher and more frequent doses than specified by the product licence may be needed.
• The laxative dose also needs to increase with increases in opioid dose.
• Consider adding in a macrogol, or a prokinetic agent such as metoclopramide, domperidone, or erythromycin 250–500 mg four times a day (off-licence use) — exclude obstruction before use.
• Consider whether additional short-term treatment for faecal loading/impaction is needed.
• If passing a stool is painful, exclude (or manage) anal fissure, painful haemorrhoids, or local tumour.
• If neurological gut dysmotility is present, consider a weekly dose of sodium picosulfate.
• Seek specialist advice if constipation still persists despite these measures.

In depth

• Bisacodyl: 20 mg three times a day (off-licence).
• Co-danthramer strong: 3 capsules three times a day or 10 mL twice a day (off licence).
• Co-danthrusate: 3 capsules or 15 mL twice a day (off-licence).
• Docusate: 200 mg three times a day (off licence).
• Lactulose: titrate from 15 mL twice a day, according to need.
• Macrogol 3350:
• For constipation: 3 sachets per day.
• For high faecal impaction/loading: 8 sachets dissolved in 1 Litre of water and drunk within 6 hours. Limit to 2 sachets (250 mL/hour) in heart failure.
• Macrogol 4000: 2 sachets per day.
• Senna: 22.5 mg (3 tablets or 15 mL) three times a day (off licence).
• Sodium picosulfate: 30 mg per day (off licence).

In depth