Annular Pancreas causing bilious or nonbilious vomit

On pg 339 of FA 2016 states that annular pancreas cause non bilious vomit
However, multiple sources says that it causes bilious vomit.
Which one is right?
I just cannot ignore FA.
It is my bible for my step.

Source: Student Doctor Network - June 9, 2016 Category: Universities & Medical Training Authors: jaehyun83 Source Type: forums