<<Disclaimer: Verify this information before applying it to your situation.>> Just my advice....Stay on the Gluten Free Diet! If your are a serious Celiac victim, the damage from Gluten will definitely not be healed in the time for the biopsy. The Biopsy will certainly prove if the celia in the bowel area are flattened and affecting your absorption of nutrients. I would say that this would not be noticable unless you were Gluten Free for several months. Jimbo99.aol.com