Children suffering from epilepsy would be eligible to use a form of medical marijuana under a measure that gained bipartisan approval in the Illinois House this week.

Legislation allowing minors with epilepsy to use cannabidiol, a cannabis derivative, passed 98-18 on Wednesday with support from several Republican lawmakers who had previously opposed the law, the Chicago Sun-Times reports.

Support for legalizing cannabidiol, or CBD oil, is spreading in the U.S. -- even in traditionally conservative states. Floridaand South Carolina are considering legislation on CBD oil, already legal for patients with some conditions in Colorado, Kentucky, Mississippi, Tennessee, Utah and Wisconsin.

Meanwhile, the clock is winding down on the Illinois General Assembly's spring session, with little more than a week left for the state Senate to approve the bill.

"It's crucial that the Illinois Senate passes the measure quickly," Nicole Gross, one of the Illinois parents of children who have epilepsy who lobbied for the bill, told The Huffington Post Thursday.

With few options, Gross moved with her two young children from Naperville, Illinois, to the Denver area in December. In Colorado, which has generous CBD oil treatment laws for minors, Gross can use the drug to quell her son's intractable seizures.

"We just don't have time to wait," Gross said. "My son has access to cannabis oil here [in Colorado], but kids in Illinois don't. They're having seizures every day or are in the hospital. It's a matter of life and death."

CBD oil has little of the high-inducing THC chemical found in the marijuana plant, and parents say it lacks the hellish side-effects of anti-seizure prescription drugs. Many have left their home states for Colorado to secure medical marijuana therapy for their children.

Though Gross said she's lucky to have family in Colorado to live with, her husband, Randy, must remain in Naperville for work.

"It puts parents in an extremely difficult situation," Gross said. "You can stay where you are and face the possibly [your child] may not wake up the next morning from SUDEP" -- or sudden unexpected death in epileps -- "Or do you move to another state, but be separated from your home and family?"

Under Illinois' medical marijuana pilot program, the nation's strictest, only those aged 18 and older are eligible for the state's medical marijuana registry, and epilepsy is not among 40 medical conditions that qualify for medical marijuana treatment.

In the few months that Gross' son, Chase, has been using the CBD oil, Gross said he has "60 to 90 percent seizure control," even when he's sick or injured. "You can really see his personality now."

Before getting the treatment, Chase suffered seizures as often as every few seconds. Gross said the seizures are akin to "having a constant electrical shock, like having your brain reset. It's not like passing out, but it's almost like your brain shutting down. And this happens thousands of times a day."

Seizures left Chase unable to play and function independently.

"He can't recall what he was doing a minute ago," Gross said, "For kids who have epilepsy, they have constant headaches. These kids don't understand why this is happening to them. They'll have a seizure and fall and hit the ground and then they have no idea what happened."

Lawmakers who oppose the use of medical marijuana derivatives say they don't want to see the drug legalized further, The Associated Press reports.

But they aren't the only hurdle. Treating minors with medical marijuana remains controversial among pediatricians. Some families have switched doctors just to secure the treatment for their kids.

"I think the biggest struggle will be finding doctors who are willing to sign off on medical marijuana treatment," Gross said.

In addition to doctors, parents will have to ensure marijuana growers cultivate strains of cannabis that are best for epileptic kids -- high in CBD and low in THC -- like the popular "Charlotte's Web" variety.

The Illinois bill initially passed the state Senate in April, but it must be re-approved following changes that would allow medicinal marijuana treatment for minors with not just epilepsy, but other debilitating medical conditions, including cancer and Crohn’s disease.

While Gross said she's happy about the state House approval, she'll feel better once the bill is on Gov. Pat Quinn's (D) desk.