I have been on Kuvan for over a year now and I haven’t experienced any side effects. Have you mentioned this to your clinic? They might be able to tell you if this is a side effect or not. I know any major change in diet can cause problems like constipation, PKU or not.
I’m on Kuvan now for a couple months.I started with heartburn,and my Dr. cut out 1 pill a day,and now i have none. nDo what Bre said,and notify the Dr. Also check on what he’s eating especially if theres been an increase on certain foods it can cause constipation. Tracie-PKU