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A useful definition of constipation is 'the passage of hard stools less frequently than the patient's own normal pattern.' The Bristol stool form scale is a means of assessing intestinal transit time.

  • Types 1 and 2 indicate constipation: will be passed infrequently
  • Types 3 and 4 indicate 'normal' ideal stools; should be passed once every 1-3 days, depending on individual normal bowel emptying patterns.
  • Type 5 to 7 suggest diarrhoea or urgency; passed very frequently.
The Bristol Stool Chart is available at: Women may be more likely to experience constipation very early in pregnancy as a result of hormonal changes. Constipation is a common side effect of iron supplementation. Management involves increasing dietary fibre, exercise, and drinking plenty of water. If dietary changes are insufficient to alleviate constipation, a laxative can be used. Those that are safe to use in pregnancy include lactulose and macrogols, which are not absorbed by the digestive tract. Stimulant laxatives such as senna may be unsuitable in later pregnancy because they are partially absorbed.

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