The lawsuit filed Thursday says the changes create overwhelming obstacles for suffering patients. It asks a judge to set aside the overhaul passed by lawmakers and keep the original law that won with 53 percent of the vote.
The pre-Election Day compromise agreement secured the support of The Church of Jesus Christ of Latter-day Saints. The lawsuit also says leaders in the faith wielded too much power over the process.
Legislators can change the language of laws passed by voters under Utah law.