Utah legislators have sent Gov. Gary Herbert a bill that would allow use of cannabis oils by a small group of children who suffer from untreatable epilepsy. If the bill is signed into law, Utah would join a growing number of states that allow some form of medical use of plants also used to make marijuana.

The bill, approved by Utah's Republican-dominated legislature Thursday, would allow an estimated 50 children in the state who suffer from severe and potentially fatal epileptic seizures to be treated on a trial basis with...