Health and Human Services Secretary Alex Azar was treated in Indianapolis for an infection. (Melina Mara/The Washington Post)

Health and Human Services Secretary Alex Azar said Monday that he had been discharged from an Indianapolis hospital after an overnight stay for treatment for an infection.

In an early afternoon tweet, Azar, 50, thanked the “incredible doctors and nurses who provided me with excellent care,” as well as his wife, “who insisted that I call my primary care doctor when I wasn’t feeling well.”

Neither Azar nor HHS officials who announced his Sunday night hospitalization disclosed the nature of his infection. The initial announcement said he had been treated with intravenous antibiotics and admitted to an undisclosed hospital.

On Tuesday morning, an HHS spokesperson who spoke on condition of anonymity to discuss private medical issues said that Azar was diagnosed with diverticulitis, his first bout of the infection, which strikes the walls of the colon. The secretary is going to be on a modified schedule in coming days, including a postponement of a Senate budget hearing at which he was scheduled to testify on Thursday. “He is hard-charging. This is a forced slowdown,” the spokesperson said.

HHS officials announced on Monday that Azar would return to Washington on Tuesday, after having been hospitalized overnight in Indianapolis, where he spends many weeks because his family is still living there. The spokesperson said the timing of his return “could be subject to change,” but added, “Wherever he is, he is working.”

In his tweet, Azar said he had been at St. Vincent’s Hospital in Indianapolis, part of Ascension, a large Catholic health system. Azar’s family has not yet moved to Washington, and he returns on many weekends to Indianapolis, where he previously led the U.S. affiliate of the pharmaceutical manufacturer Eli Lilly, which is based there.

“Glad to be back at work for the American people,” Azar said in his tweet.

He became secretary of HHS, the government’s largest domestic agency, in late January, succeeding the Trump administration’s first HHS leader, Tom Price, who left in the fall amid reports that he had used private charter planes while traveling on official business.

In a follow-up statement, HHS officials said that Azar was “fully functional” during his hospitalization and was in “regular contact” with other leaders of the department.