Our objective of this study was to describe the clinical course of severe functional constipation in early childhood. Eligible patients were 47 children (60% boys; median age, 3.5 months) who had constipation in their first year of life. Follow-up data were obtained through a standardized questionnaire. Success was defined as a period of at least 4 weeks with > or =3 painless bowel movements per week. Six months after initial evaluation, 69% of the children were recovered. After initial success, a relapse occurred in 15% of the children within 3 years. A duration of symptoms <3 months before referral correlated significantly with better outcome. We conclude that most infants with severe constipation evaluated at a tertiary center are recovered after 6 months. Early therapeutic intervention may beneficially contribute to the resolution of constipation.