Usually the divergence comes in the definition of "broken" and "bread-like". I've observed congregations using "mini-marshmallows" and unbroken rice chex.
Book 2, 20.4.2
Members with food allergies, such as gluten intolerance, should inform a member of the bishopric. The bishopric discusses with the members what adaptations may be appropriate for the sacrament. Members may provide their own allergen-free bread or another broken breadlike substitute in a sealed plastic bag and give it to a priesthood holder to place on a separate tray.
The bishopric may modify the procedure as necessary and can help priesthood holders identify members to whom the allergen-free item should be passed.
See disability.ChurchofJesusChrist.org for more information.
disability.ChurchofJesusChrist.org
How can those with food allergies safely partake of the sacrament?
Leaders and teachers should be sensitive to the physical and emotional impact food allergies have on an individual and should develop ways to safely include people in all activities and worship—including partaking of the sacrament. The guidelines below may help:
Members with food allergies, such as gluten intolerance or other conditions, should inform a member of the bishopric and discuss with him what adaptations may be appropriate for the sacrament.
Members may provide their own allergen-free bread or other broken bread-like substitute. Members may bring a prebroken bread substitute in a sealed plastic bag and give it to a priesthood holder to place on a separate tray.
During the sacrament, the priesthood holders break the regular bread but do not open the bags or touch the allergen-free bread substitute. The prayer to bless the bread is offered in the normal way.
The bishopric sees that the priesthood holders can identify members to whom the allergen-free item should be passed. Those who prepare, administer, and pass the sacrament should receive training on how to avoid cross contamination.
Depending on the number of individuals involved or specific circumstances, the bishopric may modify the procedure.