History and exam

Key diagnostic factors

common

presence of risk factors

Risk factors include: age >65, female, reduced fibre intake, sedentary lifestyle, and use of medicines that induce constipation.

infrequent stools

One of the features used by the American College of Gastroenterology to describe constipation.[4] Patients use this feature less frequently to describe constipation.[1][2][3]

The Rome IV criteria use a frequency of <3 defecations per week as 1 out of 6 factors; 2 out of the 6 factors must be present to make the diagnosis.[6][7]

difficult defecation

One of the features used by the American College of Gastroenterology to describe constipation.[4]

There may be failed or lengthy attempts to defecate.

sensation of incomplete evacuation

Frequently used by patients to describe constipation.

excessive straining

Frequently used by patients to describe constipation.

Other diagnostic factors

common

hard stools

Frequently used by patients to describe constipation. Stool consistency may be rated using the Bristol stool form scale.

uncommon

abdominal mass

Presence of stool in the left or right lower abdominal quadrants may be palpated. Other abdominal masses may indicate a secondary cause, such as a tumour.

signs suggestive of underlying medical disorder

Detailed physical examination to evaluate for signs of neuropathy, diabetes, hypothyroidism, gastrointestinal cancer, and neurological disorders should be performed.

Alarm features detected from the history or exam include rectal bleeding, haem-positive stool, weight loss, obstructive symptoms, recent onset of symptoms, rectal prolapse, change in stool calibre, age >50 years.

anorectal lesions

Anorectal inspection can detect skin excoriation, skin tags, anal fissures, or haemorrhoids.

Assessment of perineal sensation and anocutaneous reflex by gently stroking the perianal skin with a cotton bud (Q-tip) or blunt needle in all four quadrants will elicit reflex contraction of the external anal sphincter. If this reflex is absent, a neuropathy should be suspected.

abnormality on digital rectal examination (DRE)

DRE may reveal a stricture, spasm, tenderness, mass, blood, stool, or rectocele.

If stool is present, its consistency should be noted and the patient should be asked if they were aware of its presence. A lack of awareness of stool in the rectum may suggest rectal hyposensitivity.

Assessing the resting and squeeze tone of the anal sphincter and puborectalis muscle is done by asking the subject to squeeze. The subject should be asked to push and bear down as if to defecate. During this manoeuvre the examiner should perceive relaxation of the external anal sphincter and/or the puborectalis muscle, together with perineal descent. A hand placed on the abdomen can gauge the abdominal push effort. An absence of these normal findings should raise the index of suspicion for an evacuation disorder such as dyssynergic defecation.[8]

Risk factors

strong

female sex

Constipation is about twice as common in women as in men.[11][12][16]​​​​

weak

age >65 years

Prevalence of constipation is thought to increase with advancing age, although some systematic reviews have reported conflicting data or lack of association.[12][13][17][18]​​​​​ Older people report more problems with difficult bowel movements (straining, hard stools) than infrequency.[28] 

African ancestry

Prevalence of constipation is twofold higher in black people, according to one systematic review.[2]

lower socioeconomic status

Several studies report that constipation is more common among patients of lower socioeconomic status, but systematic reviews have found inconsistent data and suggest this association may vary by country.[11][17]

family history

One survey showed familial susceptibility, with a higher prevalence in sisters, daughters, and mothers of constipated women, with an odds ratio of 3.8.[29]

sedentary lifestyle

In one longitudinal study of Australian women, constipation was less common in women who performed low to moderate exercise than in sedentary women.[30] In another study of older adults, constipation was less prevalent in those who walked 0.5 km/day versus those who had restricted mobility.[31]

low fibre intake

A high-fibre diet increases stool weight and accelerates colonic transit time.[32]​ In contrast, diet deficient in fibre may lead to constipation.​[33] However, there is no evidence that patients with constipation in general consume less fibre than patients without constipation; in fact, studies show similar levels of fibre intake.[17][34]

inadequate calorie intake

Inadequate caloric intake can cause constipation, and constipation is a recognised problem in patients with anorexia nervosa.[35] Re-feeding and restoration of normal weight is associated with an acceleration of colonic transit.[36]

inadequate fluid intake

May be associated with constipation. However, evidence suggests that increased fluid intake alone does not improve constipation in patients who are not dehydrated.[18]

surgical procedures and childbirth

A detailed history should be obtained, including any history of abdominal surgeries, vaginal deliveries, need for episiotomy, and obstetric injuries.

use of drugs that induce constipation

A complete list of current drugs should be obtained in order to evaluate for drug-induced constipation. Drugs such as opioids, calcium-channel blockers, antipsychotics, and tricyclic antidepressants may cause constipation. Up to 81% of patients using opioids experience constipation.[18]

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