Washington (CNN) -- A bi-partisan group of lawmakers lashed out at officials from the Veterans Affairs Department on Wednesday, accusing the agency of allowing veterans to die from delayed or absent medical care at its facilities and stonewalling a follow-up congressional inquiry.
Barry Coates, 44, said at an unusually emotional U.S. House hearing that he is dying of cancer because a simple medical procedure was delayed at several VA facilities, including the William Jennings Bryan Dorn VA medical center in Columbia, South Carolina.
Coates, who was featured in a CNN investigation in January about delayed care and veterans' deaths, testified how for a year he complained to VA doctors about his excruciating pain and rectal bleeding.
The Army veteran went to several VA clinics and hospitals in South Carolina, trying to get help. But the VA's diagnosis was hemorrhoids, and aside from simple pain medication he was told he might need a colonoscopy.
"Due to the inadequate and lack of follow up care I received through the VA system, I stand before you terminally ill today," Coates told members of the House Committee on Veterans' Affairs.
The CNN investigative piece found that at least 19 veterans died because of delays in simple medical screenings like colonoscopies or endoscopies at various VA facilities, according to an internal agency document.
They were among 82 people who have died or are dying or have suffered serious injuries as a result of delayed diagnosis or treatment for colonoscopies or endoscopies.
"This is an outrage! This is an American disaster!" Rep. Jackie Walorski, an Indiana Republican, nearly screamed, her voice quavering.
"My dad was a veteran. He died of colon cancer," she said crying softly. "This is so personal to me."
Rep. Julia Brownley, a California Democrat, told the VA officials she believes the number of veterans who have died from delayed or absent care is likely much higher than has been reported or been identified by the committee.
"I was very saddened to learn of the 19 deaths," she said. "But really, 19? I believe in my heart of hearts there are probably more."
Rep. Brownley asked Coates, "Have you had any formal apology from the VA?"
"None," Mr. Coates replied.
"I think it is good that we hear these stories," Dr. Thomas Lynch, a senior VA official, told the committee. "We need to learn from them, and we need to do better."
But Lynch, the VA's assistant deputy under secretary for health for clinical operations, came in for tough criticism as lawmakers grew angrier and accused agency officials of withholding information from them and delaying care.
"The department's stone wall has only grown higher and non-responsive," said Rep. Jeff Miller, the committee chairman, "There is no excuse for these incidents to have occurred."
Miller has been pushing for months to get answers about deaths and delayed care, and where the incidents occurred.
He told the hearing his committee has received virtually no answers.
"This committee has reviewed at least 18 preventable deaths that occurred because of mismanagement, improper infection control practices, and a host of other maladies plaguing the VA health care system nationwide," Miller said.
He asked Lynch repeatedly when the committee would get more details.
Just before the hearing, the VA provided the panel with the first precise details of some veterans who died in various facilities.
"I don't mean to sound like a broken record," Lynch told him. "We know you take this seriously. We will get back to you."
Asked if he was aware of Coates's situation, Lynch said: "I have not received specifics of his situation and I assure you I will."
Lynch testified that the "VA is committed to consistently delivering exceptional health care, which our veterans have earned and deserve. ... Regrettably, as in any large health care system, errors do occur.
The "VA constantly strives to eliminate administrative and systemic errors, including those attributed to leadership and training shortfalls," he said.
But as Lynch continued, the committee leaders grew more exasperated.
"I'm very angry," said Rep. Dan Benishek, a Michigan Republican. "This man did not receive the standard of care. ... He did not even receive an apology. It's hard to understand."
Lynch told Benishek that "I'm angry as well," and "I share your frustration."
CNN's Jessica Jimenez contributed to this report.