When Joe Tobler woke up, he wondered why the doctor hadn’t performed his colonoscopy.

“They told me they finished, everything was fine and I could go home,” said the 6-foot, 275-pound Tobler, who slept through the 20-minute exam. Thanks to a sedative, he didn’t feel a thing.

But getting Tobler to go through with the exam in the first place took some coaxing.

“My doctor told me that I had to do it when I turned 50, no exceptions,” said Tobler, 53, who put off the procedure for three years. “We would rather get shot at or even killed than go do something like that.’’

Now Tobler is quick to share his story with his friends to persuade them to get checked. Colorectal cancer, which develops from smaller growths called “polyps,” is the third leading cause of cancer-related deaths in men, behind lung cancer and prostate cancer.

But colon cancer continues to kill a disproportionate number of African Americans, often because it is not caught early enough through screenings. A study published in December in the Journal of Clinical Oncology bore this out. The authors documented colon cancer mortality rates in the United States from 1985 to 2008. While the mortality rates decreased for both blacks and white, the decreases were smaller for blacks than whites. For cancer in the early, localized stages, mortality rates decreased 30.3 percent in whites, compared with 13.2 percent in blacks during this period. For cancer in the later, distant stage, mortality rates declined 32.6 percent in whites, versus only 4.6 percent in blacks, the study’s authors found.

“Mr. Tobler’s statement speaks volumes about barriers that prevent black men from getting screened,” said Dr. Daniel Sussman, a gastroenterologist and assistant professor at the University of Miami’s Miller School of Medicine. “The truth is that colon cancer screening is a simple process that saves lives.”

Sussman and his colleagues have participated in a local outreach project that looks for blood in the stool, noting these procedures are simpler and cost less.

But Sussman says the gold standard is the colonoscopy, in which a doctor uses a small tube to look for polyps inside the colon. A polyp is a clump of cells that forms on the colon lining. Over time, it can become cancerous, a risk that increases if you are over 50, overweight, smoke, have a poor diet and a family history of colon cancer.

Colorectal cancer in blacks is often diagnosed at a later stage, when it is far more dangerous. When compared to white males, black men 60 and older are at a higher risk of having polyps exceeding 9 millimeters — or about the size of a bullet — according to a recent study published in the Journal of the American Medical Association.

“If you get diagnosed at an advanced stage, it is less likely to be curable,” said Sussman, who noted that advanced-stage colon cancer requires more difficult options like surgery, chemotherapy and radiation.

“Black men do not have to die from something that is completely preventable,” said Robert Williams, who recently turned 50. “We need to be more proactive when it comes to taking care of ourselves.”

Williams says he wants to get screened “as soon as possible,” though he hasn’t done so yet. The American College of Gastroenterology recommends that black men start screenings by age 45, and that all people should begin screenings by age 50. If you have a family history of colon cancer, weight loss or rectal bleeding, screenings should begin earlier and done more frequently.

Looking back, Tobler said that a “real” man should make decisions that put his wife, children and family first. For years, he questioned whether something was amiss in his colon every time he heard noises and rumbling inside. Then he pointed to his stomach.

“When you look at a map of the colon, it looks like a big question mark,” said Tobler, who thinks of it as a metaphor for black men to ask themselves, “When will I get mine checked?”