• Where possible alleviate contributing factors (e.g. inadequate diet, dehydration, having to use a bedpan, lack of privacy, anal fissure, painful haemorrhoids, or local tumour).
• Start treatment with a combination of a stimulant and a softening laxative.
• Titrate the dose of laxatives every few days to achieve comfortable defecation.
• High (off-licence) doses may be needed to achieve this, particularly for people taking opioid analgesics.
• Relieve faecal loading/impaction, if present. Hard impacted stools may need softening before a purgative effect is aimed for.
• When introducing an opioid (or other constipating drug) advise the person of the risks of constipation and prescribe a laxative to prevent constipation.
• If the response to laxatives is insufficient:
• Exclude obstruction.
• Consider adding in a macrogol, or a prokinetic drug such as metoclopramide, domperidone, or erythromycin.
• If neurological gut dysmotility is present, consider a weekly dose of sodium picosulfate.

• When introducing a constipating drug advise the person of the risks of constipation, and consider also prescribing a laxative.
• People taking opioid analgesics should take a stimulant laxative and a softening laxative.

• This recommendation is pragmatic advice based on expert opinion [Twycross and Wilcock, 2007].

Clarify the person's understanding of the problem, and confirm the diagnosis of constipation:

• What does the person believe to be normal bowel movements?
• What is their normal pattern of defecation?
• When did constipation first become a problem?
• If constipation pre-dates the illness requiring palliative care, further enquiry may be indicated.
• What is the frequency and character of stools, and how have they changed?
• What is the frequency of defecation now, and what was it before constipation became a problem?
• Are stools sometimes loose, or are they soft and formed?
• Loose stools are not always due to diarrhoea; they may be the result of an excessively high dose of laxatives, or they may be from colonic contents soft enough to bypass hard impacted faeces.
• Ribbon-like stools suggest haemorrhoids or anal stenosis or irritable bowel syndrome.
• Are they always hard?
• Are they large (e.g. do they sometimes block the toilet)? Or, are they small, like pebbles?
• Is there discomfort with defecation?
• Is there blood or mucus with the stool?
• Suggests haemorrhoids, tumour, or colitis.
• Is straining necessary?
• Stool emerging partway through a bulging anal outlet after significant straining suggests haemorrhoids.
• Ineffective straining suggests faecal loading/impaction.

Assess the presence and degree of faecal loading/impaction and faecal incontinence:

• Can faecal masses be felt when palpating the lower left abdomen or when examining the rectum?
• Is there faecal incontinence, or loose stools?
• Have manual measures been necessary to relieve faecal loading/impaction?
• A finger having to be inserted into the vagina suggests a rectocele.
• A finger in the rectum to push away a flap suggests a rectal ulcer.
• Pressure behind the anus assists defecation if the levator muscles are weak.
• Digital rectal evacuation of faeces confirms severe faecal loading/impaction.

Assess the severity and impact of the constipation and, if present, faecal incontinence:

• Is there nausea, vomiting, loss of appetite, or loss of body weight?
• Is there abdominal pain or abdominal distension?
• Is there pain or bleeding with passing stools?
• Is underwear regularly and involuntarily soiled? If yes, what are the social consequences of this?

Assess the role (and potential for modification) of predisposing factors and drugs:

• Is the diet adequate, especially in terms of fibre. Is the person dehydrated?
• Is access to the toilet difficult? Is there a lack of privacy (auditory and visual)?
• Is mobility significantly restricted?
• Is the person using opiates or other constipating drugs?

Identify any direct effects of malignant tumour or other concurrent disease that could cause constipation:

• Does the person have a history or features of:
• Obstructive colonic mass lesions (e.g. colorectal cancer)?
• Careful examination can usually distinguish a faecal mass from a tumour or cyst: firm pressure exerted by a finger will leave a palpable indentation in hard faeces.
• Damage to the spinal cord or nerve supply of the gut.
• An endocrine or metabolic disease, a myopathic condition, a neurological disease?
• Irritable bowel syndrome?
• Anal fissure, haemorrhoids, rectal prolapse, or rectocele?
• Colonic strictures (following diverticulitis, ischaemia, surgery)?
• Inflammatory bowel disease?
• Pelvic floor dyssynergia?
• Having to strain, feeling of incomplete evacuation.

Assess effectiveness of management to date:

• What measures (self-care and prescribed, non-drug and drug) have been tried?
• What has been the response?

[Sykes, 2004]

• Confirm that the person is constipated.
• 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 laxative and 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. However, a softening laxative will often be required later on, particularly if the person is taking any constipating drugs (e.g. opioids).
• Titrate the dose every few days to achieve comfortable defecation. Comfort is more important than the frequency or number of stools.
• It may be necessary to exceed the licenced dose and frequency.
• Adjust dose of laxative in line with dose of opioid.

• Approximate equivalent stimulant plus softening laxative combinations [Regnard et al, 2004]:
• Three senna tablets (or 15 mL senna syrup) plus 15 mL lactulose.
• Three senna tablets (or 15 mL senna syrup) plus 300 mg docusate.
• Six co-danthramer capsules (or 30 mL co-danthramer syrup).
• Four co-danthramer strong capsules (or 10 mL co-danthramer strong syrup).
• Three co-danthrusate capsules.

• There is no good evidence from clinical trials to choose between alternative laxatives for treating constipation in palliative care.
• However, there is good consensus between experts that the combination of a stimulant with a softening laxative is effective for constipation in palliative care, including opioid-induced constipation [Regnard et al, 2004; Sykes, 2004; Pan-Glasgow Palliative Care Algorithm Group, 2005; Arthur Rank House, 2006; West Lancs Southport & Formby Specialist Palliative Care Services, 2006].
• There is also consensus between experts that the dose of laxatives should be titrated upwards until constipation is effectively controlled. This means that much higher doses and more frequent dosing than those specified on the Product Licence are often required to manage constipation (particularly opioid-induced constipation) effectively [Fallon and O'Neill, 1998; Twycross and Wilcock, 2007].
• Constipation due to opioid analgesics is an ongoing problem as tolerance does not develop. There is no linear relationship between morphine dose and the level of constipation [Fallon and Hanks, 1999] — some people will require small dose increases and some people will require larger dose increases to counteract constipation with an increase in morphine dose.
• Bulk-forming laxatives are less useful for palliative care constipation because:
• Their consistency is unpalatable and they need to be taken with at least 200–300 mL water, which makes them unacceptable to many ill people.
• If inadequate water is taken, they can cause intestinal obstruction. This may happen quickly if there is already partial obstruction due to a tumour.
• Although increasing fluids and dietary fibre can help constipation, it can be difficult for some people to manage this, particularly if they have little appetite. It is more important to offer them food and drink that they like.

• Start treatment with a combination of a stimulant and softening laxative. This is likely to need to be continued once impaction has been cleared.
• When the response to initial treatment is insufficient or not fast enough:
• For high faecal impaction/loading (i.e. stool not present in the rectum), consider bowel washout with a macrogol.
• E.g. Movicol^® 8 sachets dissolved in 1 Litre of water taken over 6 hours by mouth. Keep solution in a refrigerator during treatment. In heart failure limit to 2 sachets (250 mL) per hour.
• 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 (softener and weak stimulant) or sodium citrate (osmotic).
• 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 manual evacuation (using a topical anaesthetic gel and sedative cover) should be considered.

• The aim of treatment is to achieve complete disimpaction, with the minimum of discomfort. This may require several days during which doses and combinations of laxatives are adjusted.
• Enemas should be administered by a district nurse or carer.
• For more information see Advantages/disadvantages of laxatives.

• There is no evidence from clinical trials to choose between alternative strategies for treating faecal loading/impaction in palliative care.
• The recommendations for treatment are therefore pragmatically based on a synthesis of published expert opinion [Regnard et al, 2004; Sykes, 2004; Pan-Glasgow Palliative Care Algorithm Group, 2005; Arthur Rank House, 2006; West Lancs Southport & Formby Specialist Palliative Care Services, 2006].

• 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 whether additional short-term treatment for faecal loading/impaction is needed.
• Consider adding in a macrogol, or a prokinetic drug such as metoclopramide, domperidone, or erythromycin 250–500 mg four times a day (off-licence use) — exclude obstruction before use.
• 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.
• Neurological gut dysmotility is more likely in people with other neurological symptoms or signs, diabetes, small cell lung cancer, a history of chemotherapy with vinca alkaloids or platinum, a history of long term laxative abuse, or resistance to usual laxatives.
• Seek specialist advice if constipation still persists — a switch to another possibly less constipating opioid may be considered (e.g. fentanyl, methadone) but dose conversion may be difficult so specialist advice is advised.

• These recommendations are pragmatically based on a synthesis of published expert opinion [Regnard et al, 2004; Sykes, 2004].
• Constipation due to opioid analgesics is an ongoing problem as tolerance does not develop. There is no linear relationship between morphine dose and the level of constipation [Fallon and Hanks, 1999].
• There is limited evidence that suggests that switching from morphine to fentanyl or methadone may be helpful for some individuals, but this is not routine clinical practice. In addition dose conversion can be difficult and requires specialist advice.
• There is very limited evidence that suggests that adding in a peripheral opioid-antagonist such as oral naloxone (off-licence use) may also be helpful for some individuals, but this is not routine clinical practice. Naloxone is only available in the UK as a 400 microgram/mL ampoule for injection; this has a bitter taste when taken orally.