MINNEAPOLIS — Mayo Clinic is taking another step toward making detection of colorectal cancer as convenient as possible, announcing an at-home kit that arrives and is sent back in the mail, stool sample included.

In a joint announcement with Cologuard kit maker Exact Sciences of Madison, Wis., Mayo said the screening test will be available through its primary care doctors by prescription only.

Patients learn of their results in as little as two weeks from their doctor. A positive result prompts the need for a colonoscopy.

“Cologuard represents a significant advancement in identifying colorectal cancer at its most treatable stage,” Dr. Vijay Shah, chairman of gastroenterology for Mayo, said in a statement accompanying the announcement. “We believe offering this new tool will promote patient and community public health and may move more patients to get screened earlier — a critical step in beating this prevalent and preventable cancer.”

Cologuard was developed jointly by Mayo and Exact Sciences as the first — and so far, the only — noninvasive stool DNA screening test for colorectal cancer that has approval from the Food and Drug Administration.

The tests are meant for people 50 and older who are at average risk for colorectal cancer. Exact Science said it is the first noninvasive screening that analyzes both stool-based DNA and blood biomarkers to detect cancer and precancer.

Colorectal cancer is the second-leading cancer killer in the U. S.