The Liberal government's marijuana bill has returned from a parliamentary committee with a few tweaks, including a requirement that edibles and other concentrated forms of cannabis become legal within a year of Bill C-45 becoming law.

The House of Commons health committee has been studying the bill clause by clause since August, and heard from more than 100 witnesses.

Out of that process the committee put forward two key changes to the legislation earlier this week.

The original bill had a requirement that anyone who decided to grow marijuana plants at home had to limit their height to 100 centimetres and cap the number of plants they have to four. The updated bill removes any height requirements.

Many witnesses, including police officers, questioned the stipulation, arguing it didn't accomplish anything and it would be hard to enforce.

The other amendment would mean edibles and other concentrated forms of cannabis would be available within a year after the bill comes into force.

Minister of Health Ginette Petitpas Taylor arrives to testify before the start of the Commons health committee on Bill C-45, Cannabis Act, on Parliament Hill. (Justin Tang/Canadian Press)

Edible cannabis products often contain THC, the psychoactive substance that makes consumers feel high. It can come in many forms including baked goods, candy, honey, dried fruit and, as the committee heard, is sometimes preferred to smoking.

The federal government has always promised it would bring in rules for edible products later on, but there was no timeline.

"We heard from public health that limiting legalized cannabis to dried forms would encourage smoking, and there is significant public health consequences associated with smoking cannabis," Liberal MP John Oliver said when presenting the amendment.

"We also heard from many consumer groups and users that they felt that having edibles was an important piece of them being able to properly utilize the drug."

New Democrat MP Don Davies presented a similar motion.

"It's ironic that [the health committee is] going to be legalizing the one form of cannabis that is most heavily ingested by smoking and not legalizing the other forms of cannabis that present less of a harmful health impact, at least on the respiratory system," said Davies.

He added he's still concerned about the year-long wait.

"While we wait the 12 months, Canadians are still going to be getting edibles, but they're going to be getting them

from sources that are completely unregulated," he said.

The bill now returns to the House of Commons for third reading. The earliest it could be looked at is the week of Oct. 23, but the Liberals have signaled they would like to deal with it as soon as possible.

After clearing the House, it moves onto the Senate, which will do its own study of the legislation.