Constipation is one of the most common complaints in hospital, especially on the geriatric wards.
Failure to treat constipation can lead to longer hospital stays and increased morbidity.

What’s normal?

  • Anything from 3 times per day to 3 times per week is normal for adults.

What causes it?
Many things cause constipation, most commonly in hospital, it is due to:

  • Medication such as codeine
  • Lack of fibre in the diet
  • Dehydration
  • Lack of exercise
  • Embarrassment at using shared facilities/commodes/bedpans.
  • Pain on defaecation due to fissures or haemorrhoids (avoidance of passing stool)

What problems can it cause?

  • Abdominal pain
  • Confusion (part of the ‘PINCH ME’ causes of delirium)
  • Overflow diarrhoea (Always rule out constipation if a patient develops loose)
  • Nausea and loss of appetite 
  • Constipation can cause urinary retention and overflow incontinence – this is because the hard stool can pressure on your urethra. 


  • Speak to the patient – most of the time they will tell you they feel constipated
  • Do a PR examination!! It’s not as bad as you think, and in the end the patient will be grateful. 
  • The importance of this is to assess faecal impaction, which guides which laxatives you use. It can also help differentiate from overflow diarrhoea (caused by constipation) or true diarrhoea
  • You can take an enema with you so that you can administer it at the same time if necessary

Treating it with lifestyle and diet

  • Increase the amount of oral fluids
  • Increase mobility as possible
  • Recommend high fibre diets (more fruit and veg, wholemeal bread)
  • Speak to the patient and nurses about what can be done to ease anxiety over toilet facilities

Drug treatment 
There is no evidence-based guidance on the preferred order of the types of laxative. It is helpful to ask/examine for whether the stool is hard – in this case, it might be better to soften the stool first.
Most hospitals will have their own guidelines on treating constipation and which drugs are used first-line- look yours up on the intranet or ask the nurses!

Types of laxative:

  • Bulk-forming eg Fybogel – Works in a similar way to fibre. Adds bulk to your stool and softens it encouraging movement. 
    • These don’t work very well if it is opioid-induced. 
    • Start with 1 sachet BD. May take a few days to work but are thought to be more “physiological” 
  • Stimulants eg Senna/Bisacodyl – Speed up bowel movements. These work very well if your first-line treatment hasn’t worked. 
    • Initial dose 7.5 – 15ml OD (Usually given at night). Can gradually increase to 30mg daily if needed
  • Osmotic eg Lactulose – Reduces the amount of water absorbed by intestines, so the stool is softer and larger. Can cause bloating however and is sometimes not tolerated
    • Initially 10-15ml BD
    • Often used post-operatively 
  • Iso-osmotic eg Movicol – Traps fluid in the bowel to soften stool and encourages the movement of the intestine muscles. These require increased fluid intake. 
    • Be cautious in patients where the excess salt load could be harmful such as heart failure
    • Initially 1 sachet BD. 

Faecal impaction:

  • Do a PR examination to determine whether there is faecal impaction (a large amount of hard stool in the rectum)
  • Laxido or Movicol – 8 sachets a day in divided doses first line
  • Senna or Bisacodyl if the stool is soft but difficult to pass
  • Glycerol suppositories 4g daily are used as second-line
  • Enemas are used if all else fails – Phosphate enemas stimulate movement but if the stool is very hard will just cause pain! Give something to soften first eg Arachis oil enema.

Written By Dr Isabelle Hurrell (FY2)

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