Inclusion Criteria:  Adult patients with an established diagnosis of IBS-D as determined by Rome III or IV Criteria Have IBS of at least moderate severity Must be on a stable dose regimen for at least 1 month prior to enrollment Willing to follow the LEAP program for 3 months Able to give informed consent Willing to complete the study  Exclusion Criteria:  Individuals with a history of inflammatory bowel disease, celiac disease, abdominal surgeries, cancer patients under treatment, and kidney failure BMI of 40 or higher Pregnancy or planned pregnancy or lactation Any serious illness that will interfere with the study procedures or results Enrollment in active clinical trial/ experimental therapy within the last 30 days Currently on another dietary treatment approach