One of the most popular elemental diet formulas is the Physician's Elemental
Diet Dextrose-Free (Low-Carb) by Integrative Therapeutics. It is the form I use most commonly and you can try elemental diet samples prior to doing a full program.
The elemental diet is typically used for a period of 1-5 days for a gut reset or 14+ days with professional guidance for a true SIBO protocol with a weaning-off period as FODMAP foods are reintroduced.