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Published on: October 16, 2013
Effect of stool size and consistency on defecation
J J Bannister1, P Davison, J M Timms
1Department of Surgery, Royal Hallamshire Hospital, Sheffield.
Gut
|October 1, 1987
Summary
Expelling small, hard stools requires more rectal pressure and time than larger, softer ones. This difficulty is more pronounced in individuals with severe constipation.
Area of Science:
- Gastroenterology
- Physiology
Background:
- Rectal expulsion of stool is a complex physiological process.
- Understanding factors influencing defecation ease is crucial for managing constipation.
Purpose of the Study:
- To assess the impact of stool characteristics (size, consistency, compressibility) on rectal expulsion.
- To compare expulsion abilities between normal subjects and those with severe constipation.
Main Methods:
- Paired studies involving 58 normal subjects and 25 women with severe constipation.
- Expulsion of simulated stools: incompressible spheres (1.8 cm), deformable balloons (50 ml), compressible silicone stools, and wooden spheres in latex envelopes.
- Measurement of intrarectal pressure and time required for expulsion.
Main Results:
- A lower percentage of subjects expelled a 1.8 cm incompressible sphere compared to a 50 ml deformable balloon.
- Constipated patients experienced greater difficulty expelling both simulated stool types than normal subjects.
- Smaller, harder simulated stools required more intrarectal pressure and time for expulsion, especially in constipated individuals.
Conclusions:
- Stool size and consistency significantly influence the ease of rectal expulsion.
- Small, hard stools necessitate greater expulsive effort, exacerbating difficulties in patients with constipation.
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