Ronnie Turner, son of Tina Turner, passed away after a battle with colon cancer ... according to the L.A. County Coroner's Office.
TMZ has confirmed Ronnie's autopsy results, which say the 62-year-old actor died due to "complications of metastatic colon carcinoma." The coroner says the cancer was stage 4.
The report says Ronnie only struggled with cancer for 3 weeks before his death.
It's also determined Ronnie battled atherosclerotic cardiovascular disease at the time of death -- which is a buildup of fats and cholesterol in the arteries.
TMZ broke the story ... law enforcement got a 911 call Thursday morning from a person who said Ronnie was outside their home and having a hard time breathing. A few minutes later, he stopped breathing.
Paramedics rushed to the San Fernando Valley address -- where bystanders were attempting CPR, but those efforts didn't work and he was pronounced dead at the scene.
An outpouring of love has been shared for Ronnie since his death ...Tina posted a message about her son, saying, "Ronnie, you left the world far too early. In sorrow I close my eyes and think of you, my beloved son."