Table 2.

Definitions of Constipation

Rome IV criteria		Criteria used in studies of pharmacologic agents
FC	IBS-C	FC169	IBS-C170
Symptoms for ≥6 mo and 2 or more of the following symptoms for >25% of defecations during past 3 mo:  ∘ Straining  ∘ Lumpy or hard stools  ∘ Sensation of incomplete evacuation  ∘ Sensation of anorectal obstruction/blockade  ∘ Manual maneuvers to facilitate defecations;  ∘ <3 defecations/wk  ∘ Loose stools are not present, and there are insufficient criteria for IBS	Recurrent abdominal pain at least 1 d/wk in the past 3 mo associated with 2 or more of the following:  ∘ Related to defecation  ∘ Onset associated with change in frequency of stool  ∘ Onset associated with change in form (appearance) of stool  ∘ >25% of bowel movements were hard and <25% were loose stools	<3 SBMs/wk and 1 or more of the following symptoms for at least 12 wk during the preceding 12 mo  ∘ Straining in >25% of defecations  ∘ Lumpy or hard stools in >25% of defecations  ∘ Sensation of incomplete evacuation in >25% of defecations  ∘ No loose or watery SBMs (Bristol Stool Form Scale scores of 6 or 7)	Abdominal pain associated with 2 or more of the following:  ∘ Related to defecation  ∘ Onset associated with change in frequency of stool  ∘ Onset associated with change in form and (appearance) of stool  ∘ <3 SBMs and <3 CSBMs/wk; and at least 1 additional symptom  ∘ Straining in ≥25% of defecations  ∘ Lumpy or hard stools in ≥25% of defecations  ∘ Sensation of incomplete evacuation in ≥25% of defecations

CSBM, complete spontaneous bowel movements; SBM, spontaneous bowel movement.