I have finally kum to the konklusion, that a good reliable set of bowels iz wurth more tu a man, than enny quantity of brains. HENRY SHAW (1818–1885), JOSH BILLINGS
Constipation is the difficult passage of small hard stools. The Rome III criteria define it has having two or more of the following, for at least 12 weeks:
infrequent passage of stools <3/week
passage of lumpy or hard stools at least 25% of time
straining >25% of time
sensation of incomplete evacuation >25% of time
use of manual manoeuvres >25% of time
sensation of anorectal obstruction/blockage >25% of time
Accordingly it affects more than 1 in 5 in the population.1
However, the clinical emphasis should be on the consistency of the stool rather than on the frequency of defecation; for example, a person passing a hard stool with difficulty once or twice a day is regarded as constipated, but the person who passes a soft stool comfortably every two or three days does not require any diagnosis. Various causes of chronic constipation are summarised in FIGURE 31.1.
Causes of chronic constipation
Key facts and checkpoints
The survey showed 10% of adults and 6% of children reported constipation in the preceding 2 weeks.1
Up to 20% of British adults regularly take laxatives.2
Constipation from infancy may be due to Hirschsprung disorder.
Diet is the single most important factor in preventing constipation.
Beware of recent-onset constipation in the middle-aged and the elderly.
Bleeding suggests cancer, haemorrhoids, diverticular disorder and inflammatory bowel disease.
Always examine the abdomen and rectum.
Plain abdominal X-rays are generally not useful in the diagnosis of chronic constipation.
The flexible sigmoidoscope examines the lower bowel in detail.
Intractable constipation (obstipation) is a challenge at both ends of the age spectrum but improved agents have helped with management.
Using the diagnostic strategy model (see TABLE 31.1), the five self-posed questions can be answered as follows.
Table 31.1Chronic constipation: diagnostic strategy mode ||Download (.pdf) Table 31.1 Chronic constipation: diagnostic strategy mode
primary–slow transit, dyssynergic defecation
lifestyle–diet, low fluids, bad habits
Serious disorders not to be missed
Intrinsic neoplasia: colon, rectum or anus, especially colon cancer
Extrinsic malignancy (e.g. lymphoma, ovary)
Pitfalls (often missed)
Local anal lesions, e.g. fissure, haemorrhoids
Stricture, e.g. Crohn disease
Seven masquerades checklist
Diabetes (autonomic neuropathy)
Drugs (TABLE 31.2)
Thyroid disorder (hypo); hyperparathyroidism
Spinal dysfunction (severe only)
Is the patient trying to ...