Former Shattuck Hospital employees are stepping up to advocate for vulnerable patients who they say are not given the same standard of care as the rest of the population.

Dr. Catharina Armstrong and Dr. Salah Alrakawi, former physicians at Shattuck Hospital, spoke about their experiences on Greater Boston.

The two doctors were featured in a recent GBH News investigative report about surgery malpractice at the hospital that left some patients injured or in pain for life.

Armstrong and Alrakawi, who appeared on Greater Boston with GBH News' Deputy Investigative Editor Jenifer McKim, said the surgery complaints are the tip of the iceberg.

Alrakawi said there are significant disparities in how prisoners, mental health patients, immigrants, and more are cared for in the health system. Shattuck Hospital largely serves that population.

"Those people are not getting the standard of care within the city of Boston in certain fields of medicine," Alrakawi said.

He added, "We are patients' voice...unfortunately those patients cannot advocate for themselves. They don't know any better. You don't expect those patients to file a report and this and that."

Armstrong said she experienced many concerning situations, such as one incarcerated patient who received surgery on the wrong limb. She said she's speaking out in hopes of improving oversight, patient safety, patient care and support for hardworking clinicians.

Watch: ‘Tip of the iceberg’: Former Shattuck doctors recall seeing medical malpractice, workplace violence