Introduction Data regarding prevalence and natural history of infant dyschezia, defined by the Rome III criteria as straining and crying for at least 10 min before successful passage of soft stools, are lacking.

Objective We aimed to investigate prevalence and natural history of infant dyschezia.

Study design In 2003, 124 youth healthcare doctors participated in a national study on defecation patterns of infants. Using standardised questionnaires and bowel diaries, these were recorded of infants aged 1, 3 and 9 months old.

Results Out of 1292 infants, 46.4% had no gastrointestinal complaints. At 1 and 3 months old, 3.9% and 0.9% infants, respectively, fulfilled the Rome III criteria for infant dyschezia. However, at the same time points, parents of 17.3% and 6.5% of infants, respectively, reported symptoms preceding defecation while not strictly fulfilling the Rome III criteria (‘modified Rome III criteria’). Dyschezia-like symptoms (Rome III criteria) were also reported in 0.9% of 9-month-old infants, with 5.7% having symptoms (modified Rome III criteria). Only 3/61 (4.9%) Rome III dyschezia infants and 1/306 (0.3%) infants with modified Rome III criteria at 1 or 3 months had symptoms fitting the diagnosis of infant functional constipation at 9 months old.

Conclusions The present definition of infant dyschezia seems too strict. We propose to widen the definition in terms of symptoms as well as age in order to better fit the appreciation of the parents. The prevalence of infant dyschezia declines with age. There seems to be no relation to the development of functional constipation.