- Patients must fulfill the Rome III criteria of constipation, which mean they must have at least 2 of the following characteristics: fewer than 3 bowel movements weekly, more than 1 episode of fecal incontinence weekly, large stools in the rectum by digital rectal examination or palpable on abdominal examination, occasional passing of large stools, display of retentive posturing and withholding behavior, and painful defecation.