<qa>  What is the estimated prevalence of FC in Hong Kong?Functional constipation FC is a common complaint in clinical practice, with the estimated prevalence 14.3 in Hong Kong, as nearly affecting 1 million Hong Kong People in different extent. It is comparable with western population, which is 15 in North America. By the definition of Rome II criteria, FC comprises a group of functional disorders, which presents as persistent difficult, infrequent or seemingly incomplete defecation. 