| Cause of straining | Clinical characteristics |
| Infant dyschezia | - Healthy infant 0 to 9 months of age
- Soft stool passed after straining
|
| Constipation | - Healthy infant
- Stools are hard, large or pellet-like
|
| Anal fissure | - Healthy infant
- May or may not have history of constipation
- Fissure identified on inspection of anus
- Straining may be caused by voluntary stool withholding
|
| Cow's milk intolerance | - Healthy infant
- Diet contains cow's milk protein (breast- or formula-fed)
- Normal or loose stools with gross or occult blood and/or mucus
|
| Hirschsprung disease | - Newborn or infant
- History of delayed passage of meconium (after 48 hours of life)
- Well- or ill-appearing
- Constipation or abdominal distension, occasionally diarrhea
- Rectal examination may reveal tight sphincter, empty or narrow ampulla, and/or explosive squirt of stool on withdrawal of finger
- Anorectal manometry demonstrates absence of rectosphincteric relaxation reflex
- Ganglion cells absent on rectal biopsy
|
| Internal anal sphincter achalasia | - Presentation and anorectal manometry similar to Hirschsprung disease, as described above
- Ganglion cells present on rectal biopsy
|
