Peter John Crimp was convicted and sentenced to six months' supervision for cannabis possession in the Nelson District Court.

A judge has said he's "not blind to the debate" around medicinal cannabis in New Zealand during the sentencing of a man who used the drug to help him cope with Crohn's disease.

Peter John Crimp, 40, appeared in the Nelson District Court on Monday charged with possession of cannabis and a cannabis pipe.

The court heard that Crimp was driving on the Moutere Highway in the Redwood Valley about 7:50pm on September 19 when he was stopped by police.

While speaking to police, the officer noticed a strong smell of cannabis coming from the vehicle.

Police searched Crimp and his vehicle and found a small tin containing two grams of cannabis in his pocket and a small pipe.

Crimp admitted the pipe was used for smoking cannabis and told police he used it to self-medicate.

Defence lawyer Rob Ord said Crimp has Crohn's disease and used cannabis for pain relief.

"This man's lost most of his intestines," he said.

Ord said Crimp had access to morphine legally.

"The problem is he actually prefers the cannabis. He says it works for him."

Crimp believed cannabis use had prolonged his life by 10 years, Ord said.

Judge Richard Russell said it was "not appropriate" to sentence Crimp to community work and decided not to impose a fine.

"I'm not blind to the debate that's going on around the wider medicinal use of cannabis," he said.

Crimp was convicted and sentenced to six months' supervision with the condition that he completes any recommended drug counselling and treatment.

There was also an order for the destruction of the cannabis and pipe.

The family of Nelson teenager Alex Renton sparked a national debate around the use of medicinal cannabis when they campaigned on his behalf to treat his unexplained seizures with a cannabinoid oil.

Renton died on July 1 after being in an induced coma for three months. He was the first person to receive a cannabidiol product that was signed-off by a Government minister.