Diagnostic criteria*

1. Must include two or more of the following:
   1. Straining during at least 25% of defecations
   2. Lumpy or hard stools in at least 25% of defecations
   3. Sensation of incomplete evacuation for at least 25% of defecations
   4. Sensation of anorectal obstruction/blockage for at least 25% of defecations
   5. Manual maneuvers to facilitate at least 25% of defecations (e.g., digital evacuation, support of the pelvic floor)
   6. Fewer than three defecations 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

Diagnostic criterion*

Recurrent abdominal pain or discomfort** at least 3 days/month in the last 3 months associated with two or more of the following:

1. Improvement with defecation
2. Onset associated with a change in frequency of stool
3. Onset associated with a change in form (appearance) of stool

* Criterion fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis
** “Discomfort” means an uncomfortable sensation not described as pain.
In pathophysiology research and clinical trials, a pain/discomfort frequency of at least 2 days a week during screening evaluation is recommended for subject eligibility.