Team doctor Eric Bouvat said on the team website that he was diagnosed with digestive problems requiring further assessment as soon as possible.”
Gadret, 33, had struggled through the first nine stages, and was in 53rd position when he abandoned. He finished eleventh overall in the Giro d'Italia and had come to the Vuelta as the French team's captain. Gadret was third overall in the 2011 Giro.
He became only he fifth rider to abandon the race, leaving 193 riders still in the field.