Constipation is an extremely common gastro-intestinal symptom, affecting as much as a third of the population at some time. It may be very bothersome, but is usually not dangerous in any other way. In most cases it is managed symptomatically by individuals and their health care providers. However, it is important to note that it may be an indicator of another underlying condition, especially if there is recent sudden onset. In such situations it is necessary to investigate this symptom further.
The definition for constipation often used is that of fewer than 3 bowel movements per week. Some individuals have bowel movements less frequently than this, but do not experience any associated symptoms (as listed below).
For most individuals constipation is intermittent, mild and responds to symptomatic treatment. However, for some individuals it may be difficult to treat and can have a significant impact on quality of life.
Symptoms typically associated with constipation include:
- Hard stools
- Prolonged straining
- Incomplete evacuation
- Sensation of blockage when trying to pass stools
- Manual manoeuvres in order to evacuate stools
The causes of constipation are divided into “primary” and “secondary”.
"Primary constipation" is when there is not a specific identifiable disorder or cause. Also referred to as “functional constipation”, it is classified as:
- Slow transit
- Normal transit
- Obstructed defecation disorder (where there is disturbance of the normal anorectal physiology).
"Secondary causes" are when there is an identifiable disease or condition causing the constipation. Examples of secondary causes include:
- Under-active thyroid gland (hypothyroidism)
- Diabetes mellitus
- Colorectal cancer
- Neurological conditions
Secondary causes should be excluded in the following situations:
- When severe symptoms are present that are difficult to treat
- Sudden onset of symptoms (change in bowel habits)
Usual investigations performed to help differentiate between primary and secondary causes may include blood tests and colonoscopy, amongst others.