Chipotle Mexican Grill is facing hard times again after hundreds of people reportedly fell ill after eating at one of their establishments in Powell, Ohio.
“Our staff has been fielding calls all day long yesterday, so what happens when we get calls is we have to follow up and investigate.”
Whittaker says the investigation will take quite some time, and the cause of the illnesses is unclear. The district had hoped to zero in on the source by August 3, but they were unsuccessful in meeting that goal.
Health district employees will need to interview all of the customers who called the office, and the office will supply the customers with a stool-testing kit if they are willing to provide a sample. The samples will be sent to a lab for testing. So far, more than 30 kits have been delivered to people who got sick.
The stool samples will be tested for common foodborne pathogens, including salmonella, shigella, and norovirus. 
Furthermore, the district will test leftover food samples some of the customers provided.
The Powell restaurant reopened July 31 after correcting 2 health violations, 1 critical and 1 non-critical, related to pinto beans and lettuce being kept at the correct temperature. The restaurant also threw all of its food away.
Delaware County health officials say people have reported symptoms of nausea, vomiting, and diarrhea. The Delaware General Health District is asking anyone who ate at the Powell location from July 26-30 to reach out to them. 
Unfortunately, the enviro-friendly, health-conscious restaurant chain has dealt with outbreaks of food poisoning in the past. In 2015, dozens of people were sickened by E. coli after eating at Chipotle restaurants across Oregon and Washington state. Also that year, an outbreak of salmonella sickened dozens more across Minnesota.
There were numerous food poisoning outbreaks traced back to Chipotle in 2015, resulting in financial trouble for the chain and waning trust among Americans.
In response to the outbreaks, Chipotle shuttered the doors of all of its restaurants across American on February 8. 2016, to discuss with employees how the company was implementing new food-safety measures to prevent any future outbreaks, including shifting food preparation from individual kitchens to its central kitchens, blanching ingredients, and changing how it marinates chicken and steak, among other measures.
 WSB-TV Atlanta