Primary (functional) constipation is characterized using the Rome III criteria as follows:
AdultWithin the past 6 months, the following criteria must be met in three months:
| 1. at least ≥ 2 criteria must be met. | Straining during more than 25% of bowel movements |
| Hard stools in more than 25% of bowel movements | |
| Feeling of incomplete evacuation in more than 25% of bowel movements | |
| Feeling of anorectal (involving anus and rectum) tightness in more than 25% of bowel movements | |
| Manual assistance to allow defecation in more than 25% of bowel movements | |
| Fewer than three bowel movements per week | |
| 2. soft unformed stools only with laxative use (taking laxatives) | |
| 3. insufficient criteria for irritable bowel syndrome | |
Children up to 4 years old
Within the last 6 months, the following criteria must be met in three months:
| At least ≥ 2 criteria must be met | 1. two defecations (bowel movements) per week or less |
| 2. at least one episode of fecal incontinence (inability to retain stool) | |
| 3. excessive retention of stool. | |
| 4. hard or painful bowel movements | |
| 5. large fecal masses in the rectum (rectal cavity) | |
| 6. stools of large diameter | |
| Accompanying symptoms are irritability, decreased appetite, and or/.These symptoms disappear immediately after a large diameter bowel movement. | |
