RESUMO
This study aimed to evaluate the effect of dietary fiber supplementation with snack type on functional constipation. We conducted a double blind case-control study with 3 groups; placebo, low dose group (LD: insoluble fiber 7 g/d + soluble fiber 1.2 g/d) and high dose group (HD: insoluble fiber 14 g/d + soluble fiber 2.4 g/d), which were randomly assigned out of subjects with functional constipation, defined by modified Rome II criteria. We measured anthropometric parameters and evaluated the bowel movement frequency, stool type, straining, sense of complete evacuation, abdominal discomfort/pain, abdominal inflation, relief and colon transit time before, during the supplementation. Both LD and HD groups had significant improvement in straining, sense of complete evacuation and satisfactory relief compared with placebo group (p<0.05). When subdivide by baseline colon transit time (less than 24 hrs/24 hrs or more and less than 72 hrs/72 hrs or more) , only HD group had significantly improvement; colon transit time recovered near by 24 hrs in subjects of 'less than 24 hrs' (from 7.57+/-1.40 hrs to 25.2+/-3.91 hrs, p<0.01) and reduced in those of '24hr or more and less than 72 hr' (from 47.0+/-3.36 hrs to 31.3+/-4.31 hrs, p<0.01) and '72 hr or more' (from 106.7+/-10.7 hrs to 85.0+/-13.1 hrs, p<0.05) subjects. Particularly, positive effect of fiber supplementation on straining and sense of complete evacuation in test groups seemed to be greater in subjects of '24 hrs or less' and '24 hrs or more and less than 72 hrs' than those of '72 hrs or more'. In conclusion, subjects with functional constipation, particularly those having colon transit time less than 72 hrs can significantly improve, at least in part, symptom related to constipation by fiber supplementation of snack type without serious side effects.