CHICAGO (CBS) — Major shifts in marijuana laws have occurred in different states. Could Illinois be next?

Soon, it will be legal for recreational smokers to light up in Colorado and Washington state. And this week, Illinois may make marijuana use legal for some doctors’ patients, CBS 2’s Mike Parker reports.

Chicago attorney Eric Berlin is battling the painful bowel inflammation called Chron’s Disease. He hopes he and others like him can soon use marijuana legally in Illinois.

“Many, many have told me when they are flaring, they get greater relief from cannabis than any other medication,” he says.

He’s also talking about himself.

“I have used cannabis in the past, and it has helped me a great deal,” Berlin says.

Tuesday, Berlin and other advocates of medical marijuana will be in Springfield to lobby state lawmakers to approve use of drug with strict limitations.  It would only be prescribed by doctors in small amounts for sufferers of such diseases as AIDS, cancer and multiple sclerosis. The doses would be available from not-for-profit shops under state regulation.

Opposing state Rep. Jim Durkin, a west suburban Republican and a former prosecutor, worries about enforcement. He says a lot of pot from states where it’s OK’d for medical use ends up being sold on the streets here.

“Just in the last two weeks in DeKalb, there was a 10-pound traffic stop of medical marijuana that came from Oregon,” Durkin says.

North Shore Democratic state Rep. Kelly Cassidy is a co- sponsor of the bill.

“People are afraid of being tagged as soft on crime, or ‘We’ve got this slippery slope’ — that’s not what this is,” she says.

The measure’s chief sponsor is Skokie Democrat Lou Lang. He says he believes he has the 60 house votes to approve it and send it to the Senate.

“If members vote their consciences, I’d have 90 votes,” Lang says.

Lang hopes to bring it up for a vote on Wednesday in Springfield.