Chronic Idiopathic Constipation

Constipation is one of the most common gastroenterologic complaints in the general population.1,2

Although traditionally regarded as less than 3 bowel movements a week, constipation is much more than a number.1 It is a bowel condition characterized by infrequent bowel movements, and/or lumpy or hard stools, and/or difficulty with defecation.

Constipation illustration

Epidemiology

Constipation is seen in 6.9% of adults in the general U.S. population,3 and becomes more common with age.2,4 Constipation is more than twice as prevalent in women,4 who are more likely than men to use laxatives and seek health care. The prevalence is higher in older individuals, and is even more common in elderly patients receiving long-term care in hospitals or nursing homes.5

Diagnosis

For a diagnosis of chronic idiopathic constipation (CIC), symptoms should be “chronic” (persisting at least six months), and “idiopathic”, lacking another known cause.2,6 Patients should experience two or more of the following symptoms:2,6,7 

  • less than 3 bowel movements per week 
  • ≥25% of bowel movements affected by lumpy or hard stools
  • ≥25% of bowel movements affected by straining
  • ≥25% of bowel movements affected by sensation of incomplete evacuation
  • ≥25% of bowel movements affected by sensation of anorectal blockage
  • ≥25% of bowel movements affected by use of manual maneuvers to facilitate defecation

Additionally, patients with CIC rarely have loose stools without use of a laxative, and have insufficient criteria for irritable bowel syndrome.2,6,7

CIC can be further divided into 3 subtypes largely based on further physiologic testing: dyssynergic defecation (outlet obstruction), slow transit constipation (STC) and normal transit constipation (NTC).7,8,9

Pathophysiology

The pathology is multi-faceted and the 3 constipation subtypes may not be mutually exclusive, with some patients experiencing two or even three of these overlapping constipation subtypes.2,7 The symptoms of dyssynergic defecation — poor coordination between rectal and abdominal wall muscles, pelvic floor muscles and anal sphincter muscles — may co-exist with the increased rectal compliance experienced with NTC.7,10 Fewer postprandial high-amplitude propagating contractions (HAPCs) are observed in both STC, characterized primarily by reduced phasic colonic motor activity, and NTC.10

Navigating CIC

A survey of patients with chronic constipation found that the most frequent symptoms were straining (79%), hard stools (71%), abdominal discomfort (62%), bloating (57%), infrequent bowel movements (57%), and feelings of incomplete evacuation after a bowel movement (54%).6 CIC patients with abdominal symptoms also report substantial missed work, and significant financial burdens.11,12 A careful history and examination of the patient experiencing constipation is essential for taking appropriate steps to manage the condition and alleviate symptoms.2