The seal of the CIA pictured in a file photo at the spy agency’s headquarters in Langley, Virginia. (Mark Wilson/Getty Images)

As the tempo of harsh CIA interrogation of terrorism suspects increased in early 2003, an agency medical officer observed to a colleague that their role of providing an “institutional conscience and the limiting factor” for the program had clearly changed.

Medical personnel, the officer wrote in an e-mail, were becoming “the ones who are dedicated to maximizing the benefit in a safe manner and keeping everyone’s butt out of trouble.”

As described in the Senate Intelligence Committee report released this week, CIA medical doctors, as well as psychologists, were intimately involved in virtually every interrogation session to a far greater extent than was previously known.

Staff physicians from the CIA’s Office of Medical Services served as observers, with little evidence in the report that they intervened to stop the use of harsh interrogation methods.

In some cases, they warned that interrogation sessions, both planned and underway, risked exceeding guidelines they had compiled. But in most instances documented, medical personnel appear to be enablers — advising that shackles be loosened to avoid extreme edema while a detainee was subjected to prolonged standing or stress positions; covering a wound in plastic during water dousing; and administering “rectal feeding” and “rectal rehydration,” which one medical official described as an apparently effective way to “clear a person’s head” and get him to talk.

Prior to the interrogation of the first detainee in 2002, alleged al-Qaeda facilitator Abu Zubaida, the report noted, “CIA headquarters, with medical personnel participation, stated that the ‘interrogation process takes precedence over preventative medical procedures.’ ”

“So it begins,” a medical officer e-mailed to OMS headquarters in Langley, Va., after observing Abu Zubaida interrogation sessions, which included placing him in confinement boxes and waterboarding him.

Abu Zubaida “seems very resistant to the water board,” the medical officer wrote. “Longest time with the cloth over his face so far has been 17 seconds. This is sure to increase shortly. NO useful information so far. . . . He did vomit a couple of times during the water board with some beans and rice. It’s been 10 hours since he ate so this is surprising and disturbing. We plan to only feed Ensure for a while now.”

“I’m head[ing] back for another water board session,” the Aug. 4, 2002, e-mail said.

A CIA attorney who later viewed videotapes of those interrogations noted that “the person he assumed was a medical officer was dressed completely in black from head to toe, and was indistinguishable from other [interrogation] team members.”

Medical ethicists have expressed outrage at the participation of medical personnel at the sessions ever since descriptions of their role emerged in CIA and Justice Department documents released by the Obama administration in 2009.

“To some degree it’s a higher-resolution view,” Steven Miles, professor of bioethics at the University of Minnesota Medical School, said of the Senate report. “Things including the withholding of care are much more graphically displayed.”

The CIA use of techniques such as “rectal feeding” were previously unknown, said Miles, who also serves on the board of the Center for Victims of Torture. “There is no such thing as rectal feeding. It can’t physiologically be done; the colon does not have a lining on it that can absorb nutrients. . . . This thing is not any kind of medical procedure, it’s purely an instrument of causing extreme pain.”

The American Medical Association, in a statement Friday, said that “the participation of physicians in torture and coercive interrogation is a violation of core ethical values.”

In the wake of the report, Physicians for Human Rights called for health professionals to be held accountable for complicity in the program, saying that their participation “was central to providing legal protection” to those carrying it out.

But “the medical community can do damn little except say this is a bad thing to do, because you don’t know who these people are,” said George J. Annas, chair of the Department of Health Law, Bioethics and Human Rights at Boston University. Names of all CIA medical personnel are blacked out in the report.

The CIA’s Office of Medical Services is a little-known corner of the agency. Part of the Directorate of Support, it has traditionally provided employee-related health care and referrals.

Asked about the OMS, a CIA spokesman said that “CIA’s medical personnel are dedicated intelligence officers committed to upholding the highest standards of their health profession” and referred questions about their role in the detention and interrogation program to the agency’s June 2013 initial response to the draft Senate report.

That declassified document states that “medical concerns” were one reason why waterboarding was discontinued as an enhanced interrogation technique, or EIT, in 2003, and notes that medical personnel “intervened” to ensure that those being subjected to sleep deprivation were given breaks. It also notes that medical personnel were “on scene” working with interrogators in general.

The Senate report includes dozens of references to OMS personnel present at the “black sites” during interrogation sessions where EITs were used against a total of 39 detainees over a four-year period.

At one point, an OMS official complains about a conflict of interest among psychologists working on the program — contractors rather than CIA staff — who were both administering the techniques and assessing their effectiveness, “at a daily compensation reported to be $1800/day, or four times that of interrogators who could not use the technique.”

At another point, a medical officer expressed concern that the aggressive waterboarding of Khalid Sheik Mohammed, known as KSM, the alleged mastermind of the Sept. 11, 2001, attacks, was stressful for interrogators. “The requirements coming from home are really unbelievable in terms of breadth and detail,” the officer e-mailed.

In March 2003, the OMS completed draft guidelines for EITs, including waterboarding. Risks, it said, were “directly related to the number of exposures and may well accelerate as exposures increase.” It recommended an upper limit of “perhaps 20 in a week.”

During one of the 183 waterboarding sessions with KSM, the CIA reported that the medical officer present was “not concerned about regurgitated gastric acid damaging KSM’s esophagus,” because his gastric contents were so diluted by water. Later, the medical officer reported that KSM was “ingesting and aspiration a LOT of water” and that with “the new technique we are basically doing a series of near drownings.”

“I am going the extra mile to try to handle this in a non-confrontational manner,” the medical officer later reported of his interactions with interrogators.

While medical personnel expressed concerns about care of wounds suffered by Abu Zubaida, who had been shot during his capture, the report does not indicate they took action. “We are currently providing absolute minimum wound care (as evidenced by the steady deterioration of the wound)” an OMS official e-mailed to headquarters. Abu Zubaida “has no opportunity to practice any form of hygienic self care (he’s filthy), the physical nature of this phase dictates multiple stresses . . . and nutrition is bare bones (six cans of ensure daily).”

After two detainees each broke a foot during an escape attempt, medical personnel cautioned that they should not be subjected to certain EITs. The techniques were then administered while the detainees were “seated, secured to a cell wall” rather than being shackled while standing, according to internal documents quoted by the Senate report.

In a May 4, 2005, letter to the CIA, Acting Assistant Attorney General Steven Bradbury referred to several medical journal articles and posed a series of questions. Was it possible, Bradbury asked, “to tell reliably (e.g. from outward physical signs like grimaces) whether a detainee is experiencing severe pain?”

The CIA responded that “all pain is subjective, not objective,” but said that “medical officers can monitor for evidence of condition or injury that most people would consider painful.”

Medical officers “can and do ask the subject, after the interrogation session has concluded, if he is in pain,” the CIA response continued, “and have and do provide analgesics, such as Tylenol and Aleve. . . . We reiterate, that an interrogation session would be stopped if, in the judgment of the interrogators or medical personnel, medical attention was required.”

Julie Tate contributed to this report.