Who told you that you have trouble with carb digestion? And short of having something like celiac syndrome, I don't think you need a "no grain" regimen.
As far as enzyme supplements go, I only heard of them being used to prevent/relieve symptoms of indigestion (gas, etc.) but I never heard of them being touted to aide digestion.
And depending on exact sugars are causing the problems, you may need different enzymes (for example, the lactaid enzyme is specific to aide in breakdown of lactose, a milk sugar.)
Current program: 1,800 calories most days of the week; 45-60 minutes of mixed exercises (weights, cardio-kickbox, dance, athletic intervals) 6 days a week
Current goal: 135 pounds by birthday (July 14th) and to run half marathon at end of May.