Dr. Kathryn Ackerman, the U.S. team physician, said athletes from several other countries stayed in the same HOTEL as the Americans, but did not seem to get as sick. Officials did not rule out that the Americans could have gotten ill from food or drinking water.
"We're not really sure," Ackerman said. "My personal feeling is, I think it's from the lake."
A spokesman for the Rio organizing committee attributed the American team illnesses to "classic travel symptoms" and said an event doctor treated eight Americans, three Britons and three Australians for symptoms including diarrhea.
Bowman said he can't believe it was simply a coincidence that both Robinson and Peterson — young, fit, with no history of inflammatory bowel disease in their families — were stricken at roughly the same time with such similar conditions.
Robinson's illness deprived her of a chance to compete in the inaugural Olympic open water competition at Beijing. Peterson's career was sidetracked by frequent trips to the hospital and forced breaks from training for some six years.
Only after his colon was removed did the symptoms finally cease.
"Personally, I would never go in those waters again," Robinson said. "There are plenty of other wonderful bodies of water on this planet."
Peterson still competes, and won a gold medal at the recent Pan Am Games in Toronto though he failed to qualify for the Rio Games. Keller quit the sport to focus on her health, keeping her condition in check with a rigid diet and lifestyle.
"It ended Kalyn's career," Bowman said. "There was no doubt she was going to win a medal in Beijing, but she had to stop.