A condition in which a person infrequently passes hard FAECES (stools). Patients sometimes complain of straining, a feeling of incomplete evacuation of faeces, and abdominal or perianal discomfort. A healthy individual usually opens his or her bowels once daily but the frequency may vary, perhaps twice daily or once only every two or three days. Constipation is generally deﬁned as fewer than three bowel openings a week. Healthy people may have occasional bouts of constipation, usually reﬂecting a temporary change in diet or the result of taking drugs – for example, CODEINE – or any serious condition resulting in immobility, especially in elderly people.
Constipation is a chronic condition and must be distinguished from the potentially serious disorder, acute obstruction, which may have several causes (see under INTESTINE, DISEASES OF). There are several possible causes of constipation; those due to gastrointestinal disorders include:
Dietary: lack of ﬁbre; low ﬂuid consumption.
Structural: benign strictures (narrowing of gut); carcinoma of the COLON; DIVERTICULAR DISEASE.
Motility: poor bowel training when young; slow transit due to reduced muscle activity in the colon, occurring usually in women; IRRITABLE BOWEL SYNDROME (IBS); HIRSCHSPRUNG’S DISEASE.
•Defaecation: anorectal disease such as ﬁssures, HAEMORRHOIDS and CROHN’S DISEASE; impaction of faeces. Non-gastrointestinal disorders causing constipation include:
Drugs: opiates (preparations of OPIUM), iron supplements, ANTACIDS containing aluminium, ANTICHOLINERGIC drugs.
Metabolic and endocrine: DIABETES MELLITUS, pregnancy (see PREGNANCY AND LABOUR), hypothyroidism (see under THYROID GLAND, DISEASES OF).
Neurological: cerebrovascular accidents (STROKE), MULTIPLE SCLEROSIS (MS), PARKINSONISM, lesions in the SPINAL CORD. Persistent constipation for which there is no
obvious cause merits thorough investigation, and people who experience a change in bowel habits – for example, alternating constipation and diarrhoea – should also seek expert advice.
Treatment Most people with constipation will respond to a dietary supplement of ﬁbre, coupled, when appropriate, with an increase in ﬂuid intake. If this fails to work, judicious use of LAXATIVES for, say, a month is justiﬁed. Should constipation persist, investigations on the advice of a general practitioner will probably be needed; any further treatment will depend on the outcome of the investigations in which a specialist will usually be involved. Successful treatment of the cause should then return the patient’s bowel habits to normal.