Italian Ballan underwent surgery Wednesday night after stomach pain he first felt Tuesday did not go away.
"Because the pain wasn't that intense and continuous I thought it was a digestive problem," the former world road champion said.
"On Wednesday night, the pain became very intense so I went to the hospital."
BMC chief medical officer Dr. Max Testa said doctors performed exploratory surgery which found adhesions had formed where Ballan's spleen was removed in December following a crash that broke his left leg in two places and fractured a rib.
"The surgery to remove the adhesions and his appendix was very successful and he is doing well," Dr. Testa said.
"I do not think this will impact the original timetable we had for him to return to racing in four months. But he will stay off the stationary bike for a couple weeks."
Ballan, 33, said while these health scares have worried his family, everything is fine now.
"From now on, I want to look forward to the future and riding with my teammates again," he said. "No more hospitals anymore."