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. 

Diagnosis

• 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)