To determine the outcome of chronic idiopathic constipation, we followed 62 children with chronic idiopathic constipation (mean age: 5.2 +/- 2.8 years) for a period of five years. Each child received the same initial treatment over a 12-week period and was then followed every three months. After five years from diagnosis, chronic idiopathic constipation persisted in 52% of the children; 47% who remained symptomatic were > 10 years old at the time of the five-year evaluation. Of the 27 who were constipated in the first year of life, 63% remained constipated after five years. Children who recovered within the five-year interval were significantly different from those that remained symptomatic in age of onset of constipation (P < 0.05) and family history of constipation (P < 0.05). After five years, both severity of abdominal pain and degree of soiling significantly decreased in both the recovered and unrecovered groups (P < 0.05). This study suggests that chronic idiopathic constipation persists for > or = 5 years in at least half of children. Early age of onset and family history of constipation are predictive of persistence. Abdominal pain and soiling improve in long-term follow-up irrespective of constipation outcome.