Food Allergies Treatment

We had to feed the baby formula for 48 hours because of a serious colon-allergy she developed. During that time my wife pumped her milk out, up to 6 ounces at a time. Now 48 hours later her milk production has been seriously diminished, and she is receiving the baby stimulation but we are worried it might not come back to full production. You think it will come back? Has it helped you to drink oatmeal as some friends have suggested?