Colorado health officials on Friday announced a new crackdown on medical marijuana patients whose doctors have given them permission to grow more than the standard number of marijuana plants.

Starting Monday, the Colorado Health Department will send out letters to doctors who recommended the elevated plant counts and the patients who benefit, requiring them to provide more documentation on the need for the extra plants.

Dr. Larry Wolk, the department’s executive director, said doctors must provide not only medical information about the patients that caused the elevated recommendations but also studies showing that the patients’ conditions require more medical marijuana than average.

Colorado’s constitutional medical marijuana provision limits patients to six plants each unless “greater amounts were medically necessary to address the patient’s debilitating medical condition.”

“We need information,” Wolk said. “The constitution says ‘medically necessary.’ “

Wolk made the announcement Friday at a Health Department-hosted town hall meeting on medical marijuana. Also during the meeting, he unveiled a proposed bill that would strictly limit medical marijuana caregivers — people who grow cannabis for patients who can’t grow for themselves — to serving only five patients and growing no more than six plants per patient. Caregivers can currently apply for a waiver to serve more than five patients.

The announcements brought an angry response from the crowd. One medical marijuana activist shouted, “Fascist!” as Wolk spoke. Later, during public testimony, another activist cursed at Wolk.

“This is criminal,” said James Clark Jr., a caregiver from Akron who said he serves 25 patients because there are so few caregivers on the Eastern Plains. “This is mean. This is hurtful to people who are very sick.”

Advocates say the higher plant counts are needed to make edible marijuana products and concentrates, which they say are a better way to treat some patients.

Colorado has about 3,300 medical marijuana caregivers, Wolk said, and 24 of them are registered to more than five patients. One caregiver serves 82 patients.

Law enforcement officials have repeatedly raised concerns over caregivers growing for large numbers of patients or patients who can grow large numbers of plants, arguing that they could be a source of illegal marijuana sales. A state audit last year recommended that lawmakers crack down on caregivers and elevated plant counts.

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/john_ingold