Blacks need emergency surgery more often than whites for a common type of intestinal disease, and they tend to fare worse afterwards, suggests a study of older Americans on Medicare.

It’s not the first time researchers find racial differences in rates of complications and death from the disease, called diverticulitis. But those disparities have been blamed on lack of health insurance and access to care among blacks.

The new study hints there may be cultural differences or treatment disparities between races that explain why blacks are more likely to die or be sent back to the hospital after treatment, even when they have health insurance.

For example, blacks seem to be less likely to see a primary care doctor regularly, experts said, or may be treated in more-crowded, poorly-funded hospitals.

“You’re left with this very disturbing finding that the treatment of blacks and whites in the United States remains disparate,” said Dr. Selwyn Rogers, Jr., who studies inequalities in surgical care at Harvard Medical School in Boston but wasn’t involved in the new work.

“You’re more likely to die if you happen to be black,” he told Reuters Health.

In diverticulitis, pouches in the intestine become infected or inflamed. The condition may affect up to one in four elderly Americans at some point, researchers wrote in the Archives of Surgery, and can be dangerous when not caught early. It causes severe stomach pain and sometimes nausea and vomiting.

The study, led by Eric Schneider from The Johns Hopkins School of Medicine in Baltimore, included more than 50,000 patients who were treated for diverticulitis, either with emergency or elective surgery, between 2004 and 2007. All of them were at least 65 years old and covered by Medicare, the government health insurance for the elderly.

More than two-thirds of the procedures done in blacks were emergency surgeries, compared to about 55 percent of those in white patients.