Constipation
Evaluation and treatment of persistent or recurrent difficulty passing stools
What is constipation?
Constipation is defined by effort and consistency more than by frequency. Anything from three times a day to three times a week is within normal range, and the difference between comfortable and not is how hard the stool is and how much work it takes to pass.
There are three mechanisms behind it. In most people the stool simply moves too slowly through the large bowel, so more water is drawn out of it and it hardens. In a smaller group the transit is normal but the muscles of the pelvic floor tighten when they should let go, so the stool arrives and cannot get out. And in a few there is a physical narrowing in the way.
The three need different treatment, and this is why laxatives that work well for one group do very little for another. Sorting out which mechanism is at work is more useful than trying stronger and stronger laxatives.
What you might notice
- Going days without opening your bowels
- Cramping that eases after a bowel movement
- A lasting change in bowel habit
- Heaviness in the abdomen
- Bloating after meals
How it is diagnosed
The history separates most of it. Lifelong difficulty points at how the bowel or the pelvic floor is built, while a change that has begun over the last few months in an adult is treated as new until a cause is found.
Examination of the back passage is part of a first assessment and is more informative than people expect. It shows the tone at rest, whether the muscles relax or tighten when you are asked to bear down, and whether the rectum is loaded.
Blood tests check the thyroid, calcium and haemoglobin. A look at the large bowel is arranged where the pattern is new after middle age, or where there is bleeding, weight loss or a family history. Where the story suggests the pelvic floor, pressure measurements and a test of your ability to expel a small balloon give the answer directly.
Recovery
Fibre, fluid and a regular routine work slowly, and the routine is the part most often skipped. The bowel responds to habit, and sitting at the same time each day, unhurried, after a meal, does real work.
An osmotic laxative taken daily is usually given long enough to soften everything and clear a loaded rectum, which can take a fortnight or more. Taking it only on bad days keeps the cycle going.
Where the pelvic floor is at fault, retraining takes a course of sessions over several weeks and the improvement builds through them. Progress is measured by how much less straining is needed and not by the number of times a week, and the gains hold best in people who keep practising afterwards.
If it is left untreated
Constipation that answers to fibre, fluid and a routine needs nothing more, and there is no harm in managing it that way for years.
Left alone at the harder end, hard stool builds in the rectum and softer material leaks around it, which is often mistaken for diarrhoea, particularly in older people. Prolonged straining also stretches the pelvic floor and contributes to piles, fissures and prolapse over time.
The consequence worth naming is diagnostic. A change in bowel habit that has begun in an adult can be the first sign of a narrowing growth in the large bowel, and treating it as a diet problem for a year is how that is missed.
Questions about constipation
Will more fibre fix it?
For a lot of people, yes, when it is built up slowly and taken with plenty of fluid. Adding a large amount quickly causes bloating and wind, and stopping there is why many people conclude fibre does not suit them. Fibre also helps least in the group whose pelvic floor will not relax on pushing, where it can make matters worse by adding bulk that still cannot get out. That group is identified by anorectal manometry.
Is it harmful to take laxatives every day?
Osmotic laxatives such as polyethylene glycol and lactulose are designed for long-term daily use, do not damage the bowel and do not stop working. The older worry about a bowel becoming lazy came from stimulant laxatives used heavily over years, and even there the evidence is weaker than the reputation suggests. The important thing is to take enough, regularly, instead of taking a large dose only on the worst days.
What is biofeedback and does it work?
It is a course of training sessions for people whose pelvic floor muscles tighten when they should relax during a bowel movement, a pattern confirmed on anorectal manometry. A sensor shows you the pressure you are generating on a screen, which lets you learn to control muscles you cannot normally feel. It is the recommended treatment for that specific group, and it does very little for constipation caused by slow transit, so the testing beforehand is what makes it worthwhile.
Other gastroenterology treatments
Management of acid reflux and heartburn that persist, recur frequently or affect daily life
Day CareDiagnosis and treatment of inflammation of the stomach lining
Day CareTalk to a care coordinator about constipation
Leave a number and a care coordinator calls you back with what the treatment involves and which hospital it would be at. They book a consult only if you want one