Table 1.

Rome IV diagnostic criteria* for functional constipation adapted from (6)

1. Must include 2 or more of the following:**

Straining during more than one-fourth (25%) of defecations

Lumpy or hard stools (BSFS 1-2) more than one-fourth (25%) of defecations

Sensation of incomplete evacuation more than one-fourth (25%) of defecations

Sensation of anorectal obstruction/blockage more than one-fourth (25%) of defecations

Manual maneuvers to facilitate more than one fourth (25%) of defecations (e.g., digital evacuation, support of the pelvic floor)

Fewer than 3 spontaneous bowel movements per week

2. Loose stools are rarely present without the use of laxatives

3. Insufficient criteria for irritable bowel syndrome

*Criteria fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis

**For research studies, patients meeting criteria for OIC should not be given a diagnosis of FC because it is difficult to distinguish between opioid side effects and other causes of constipation. However, clinicians recognize that these 2 conditions might overlap

BSFS Bristol stool form scale, OIC opioid-induced constipation, FC functional constipation