Table 1 Scales and criteria used for patient selection

a. Rome III diagnostic criteria for functional constipation [22]

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

 - Straining during at least 25% of defecations

 - Lumpy or hard stools in at least 25% of defecations

 - Sensation of incomplete evacuation for at least 25% of defecations

 - Sensation of anorectal obstruction/blockage for at least 25% of defecations

 - Manual manoeuvres to facilitate at least 25% of defecations (e.g., digital evacuation, support of the pelvic floor)

 - 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.

b. Likert scale for the subjective evaluation of constipation [23]

0. Absent

1. Mild

2. Moderate

3. Severe

4. Very severe