Constipation

Constipation is a symptom not a diagnosis and means different things to different people. Always ask patients exactly what they mean by the term constipation. There are various formal (and different) definitions of constipation. It is defined as defecation that is unsatisfactory because of infrequent stools (<3 times weekly), difficult stool passage (with straining or discomfort), or seemingly incomplete defecation. Stools are often dry and hard, and may be abnormally large or abnormally small.¹

Patients may mean that:

• Faeces are too hard
• They do not defecate often enough for 'inner cleanliness'
• Defecation hurts
• They have diarrhoea.

A careful history helps to determine the possible cause. Ask about frequency, nature and consistency of the stool. Is there blood or mucus in/on the stools? Is there diarrhoea alternating with constipation? Has there been a recent change in bowel habit? Ask about diet and drugs.

Rectal examination is essential.

• Most constipation does not need investigation, especially young, mildly affected patients.
• Indications for investigation include:
  • Age >40yrs
  • Recent change in bowel habit
  • Associated symptoms (weight loss, rectal bleeding, mucus discharge, or tenesmus)
• Possible investigations include:
  • Blood tests: FBC , U&E , Ca2+, TFTs.
  • Sigmoidoscopy and biopsy of abnormal and normal mucosa.
  • Barium enema if suspected colorectal malignancy.
  • Special investigations (eg transit studies; anorectal physiology) are occasionally indicated.

• Treat the cause
• Mobilise the patient
• Consider drugs only if above measures fail
• Try to use drugs for short durations only

Drug therapy

This is covered in the article on Constipation in Children.