Boston College says more than 120 students have now reported gastrointestinal illnesses, and nearly all are students who ate at a Chipotle restaurant near campus.
Dr. Thomas Nary, director of university health services, announced Wednesday that the symptoms are consistent with norovirus.
A spokeswoman for the Boston Public Health Commission said the illnesses were likely caused by norovirus, but final test results aren't expected for a couple of days.
The illnesses led to the temporary closure of the restaurant in the city's Cleveland Circle neighborhood. City officials said a restaurant employee was sick during a shift last week.
A spokesman for Denver-based Chipotle Mexican Grill Inc. has said the Boston College illnesses are likely an isolated case of norovirus and unrelated to the E. coli cases that have turned up in nine states.