Watchdog finds G.O.P. congressman harassed staff and recklessly drank while serving as White House physician.

Ronny Jackson, the White House doctor who rhapsodized about Donald J. Trump’s “incredible genes” and went on to win a Texas congressional seat with Mr. Trump’s help, cursed and belittled his subordinates, drank and took sleeping pills on the job, and sexually harassed a woman, according to a detailed report released Wednesday by the Pentagon’s inspector general.

Dr. Jackson, a rear admiral in the Navy when he served as White House physician, became infamous for his rosy assessment of Mr. Trump’s “excellent health” in early 2018, when he said that had the commander in chief, 71 at the time, simply adhered to a better diet over the previous two decades, he could have lived to be 200.

His effusive praise of Mr. Trump helped win him a nomination to become the secretary of veterans affairs. But Mr. Trump abandoned the nomination several weeks later after numerous news accounts reported that Dr. Jackson was a bully to his staff, kept sloppy medical records, drank too much, and loosely dispensed strong drugs on Air Force One and in the White House to curry favor with top officials.

With the endorsement of Mr. Trump, who tweeted that “Ronny is strong on Crime and Borders, GREAT for our Military and Vets,” Dr. Jackson went on to win a Republican primary in Texas and was elected to Congress in 2020.

On Wednesday, Dr. Jackson vehemently disputed the findings of the report. In a statement released by his congressional office, he accused the Pentagon’s investigators, who are nonpartisan, of seeking to punish him for his support of Mr. Trump.

The 37-page report, which came after a nearly three-year investigation started by Glenn A. Fine, the acting inspector general for the Defense Department at the time, went further than previous news reports. It concluded that “Jackson’s overall course of conduct toward subordinates disparaged, belittled, bullied and humiliated them,” and documented instances in which Dr. Jackson was drunk or under the influence of a powerful sleeping drug while he was responsible for the president’s health and safety.

Investigators also found that Dr. Jackson had engaged in inappropriate behavior on trips abroad with Mr. Trump and former President Barack Obama, whom he also served.

In 2014, before a trip to Manila, witnesses said Dr. Jackson told a male subordinate that he thought a female medical professional they were working with had a nice figure, using colorful language, and that he would “like to see more of her tattoos.”

While in Manila, witnesses said that Dr. Jackson went out on the town for a night of drinking, came back to the hotel where the medical team was staying and began yelling and pounding on the female subordinate’s hotel room door between 1 and 2 a.m. while “visibly intoxicated.” Witnesses said he created so much noise they worried it would wake Mr. Obama.

“He had kind of bloodshot eyes,” the woman recalled to investigators. “You could smell the alcohol on his breath, and he leaned into my room and he said, ‘I need you.’ I felt really uncomfortable.”

On a separate trip to Argentina with Mr. Trump, a witness recalled that Dr. Jackson “smelled of alcohol” as he assumed his duties as the primary physician on the trip, and that the doctor had a beer a few hours before going on duty, in defiance of a policy prohibiting White House medical personnel from drinking on presidential trips. Dr. Jackson had previously recounted to witnesses that he found that rule to be “ridiculous,” investigators found.