Enzymes are not required by SCD but most parents find them to be very helpful.

There are some children who cannot tolerate enzymes during the early stages of SCD; this might be due to the protease in the enzymes. A special enzyme was made to overcome this problem: the new enzyme assists protein breakdown but avoids excessive amounts of proteases that may irritate or inflame GI tissues. View information concerning ProZymes, the new enzyme
PROZYMES IS THE BEST ENZYME FOR SCD!

If you have not used enzymes before, it might be a good idea to wait a few weeks before introducing enzymes.

List of other SCD legal enzymes:

Peptizyde by Houston Nutraceuticals, Inc.
No Fenol by Houston Nutraceuticals, Inc.
H N-Zyme Prime by Houston Nutraceuticals, Inc.

Digest Gold by Enzymedica
PLEASE BE CAREFUL: "Digest Gold" is legal but "Digest" by Enzymedica is NOT LEGAL. It needs to have the word "Gold" in its name.
Vitase Digestion Formula

EnZymAid by Kirkman Labs
Enzym-Complete/DPP IV by Kirkman Labs
Multi-Enzyme Formula by Kirkman Labs
Peptidase Complete by Kirkman Labs