Irish Olympic swimmer Daniel Wiffen said he was “disappointed” to miss Sunday’s closing ceremony at the Paris Games after being rushed to the hospital due to an illness.

The 23-year-old — who won two medals in the pool at the 2024 Olympics and swam in the long-polluted Seine River last week as part of the men’s 10-kilometer event — missed out on his flag-bearer duties to receive treatment for an unspecified “bug.”

“Thanks everyone who reached out, I’m incredibly disappointed to miss out on the opportunity to be flag bearer last night,” Wiffen wrote Sunday on X.

“Yesterday I rushed to hospital as I was very unwell with a bug that I am being treated for, and am feeling better now. I hope everyone enjoys the evening and I hope to be well enough to seeing everyone when we get home.”

Wiffen did not share further details about his illness.

It came after the Irishman swam in the Seine River, finishing 18th in the men’s 10-kilometer marathon swimming event on Aug. 9.

“It was probably one of the worst things I’ve ever done,” he told RTE afterward, vowing “never to it again.”

Wiffen explained at the time that it was his first and “last” time competing in the open water event.

“I’m retiring from open water,” he said.

Wiffen also said he was going to party after securing two medals in Paris, winning bronze in the men’s 1500-meter freestyle and gold in the men’s 800-meter freestyle, where he set an Olympic record with his time of 7:38:19 on July 29.

“You’ll see me out in the nightclubs tonight with some Guinness,” he said after the 10km race last Friday.

Swimming had been banned in the third-largest river in France for more than a century because of bacteria-contaminated waters and high levels of E. coli. It was lifted after an expensive cleanup effort was implemented in 2015.

There were even changes made in the triathlon schedule — including the cancellation of one of two open water practice sessions ahead of the men’s and women’s 10-kilometer races — due to levels of sickness-causing bacteria, according to The Associated Press.

The German committee said in a statement that three of its athletes became ill after competing in the open water races at the Paris Olympics.

“Two female German open water swimmers were treated as outpatients (Friday) for nausea, vomiting and diarrhea. They have been feeling much better since this morning,” the statement read. “Another swimmer with similar symptoms is currently being treated by the German team doctors.”

It’s unclear if their illness was linked to swimming in the Seine.

Taking to X on Monday, Wiffen explained he is ready to return home to Ireland and reflected on accomplishing a childhood dream of becoming an Olympic champion.

“They say every child has a dream, to pursue the dream is in every child hand’s to make it a reality. I had the dream of becoming an Olympic Champion,” he wrote. “I put the work in everyday and I’m so happy to say that I have accomplished my childhood dream.”

Wiffen went on to thank his friends, family, coaches and teammates who supported him in Paris.

“Now Paris 2024 is over and I head back to Ireland I can finally reflect and thank everyone for the support across the past weeks and I’m happy to say I’m bringing a Gold and Bronze home,” he said.