This study examines the effects of dietary fiber in the treatment of functional childhood constipation.

This is a 4-week double-blind, placebo-controlled study to examine the effects of dietary fiber in treating functional childhood constipation. The addition of fiber is anticipated to allow children to have more normal stool consistency and frequency.

All participants will be asked to take a snack bar twice daily and will be randomized in a 1:1:1 ratio to fiber 1, fiber 2 or placebo snack bar groups. All participants will be asked to take low-dose Miralax to avoid worsening of constipation in all groups.

Inclusion Criteria:

• 2-16 years of age with functional constipation as defined based on the Rome III criteria

Exclusion Criteria:

• Constipation attributable to organic and anatomic causes or intake of medication
• Children who had previous surgery of the colon or anus
• History of allergy/intolerance to components of snack bar (e.g. celiac disease)