Julie O'Hara August 20, 2018 Elimination Phase, FODMAP Basics, Life After FODMAP 3 Reasons Not To Stay on the FODMAP Diet Long-Term Julie O'Hara August 20, 2018 Elimination Phase, FODMAP Basics, Life After FODMAP The FODMAP elimination stage should last 4 to 8 weeks. Read the 3 key reasons why you should complete BOTH phases of the FODMAP diet and bring the foods that don’t trigger your symptoms back into your life.