Elastase Test--- with or without enzymes??

My son's GI ordered his first fecal elastase 1 test today. He has been on enzymes for a few years as an "experiment" to see if they would help his constipation & promote weight gain, but he's never been given a dx of either PS or PI. The GI said that we should stop the enzymes for about a week before the test so the results will be accurate. From what I've read online the enzymes won't affect the test, but I would hope that the Dr. knows what she's talking about. What have you done before collecting a sample? Should I stop giving him enzymes? Thanks!
Source: Cystic Fibrosis Families Forum - Category: Respiratory Medicine Authors: Tags: Families Source Type: forums