According to a letter sent to parents, multiple people became ill after going to the high school prom Saturday.
The Allegan County Health Department was notified of the outbreak.
The health department is currently gathering symptom and exposure information from students at Plainwell High School regardless of their health status.
They are asking that students complete this survey as soon as possible.
Anyone in the Allegan County area who has experienced nausea, vomiting, diarrhea or abdominal cramps since May 10 is asked to contact the Allegan County Health Department at 269-673-5411.
If you know someone from outside the Plainwell school district that attended their prom, the health department is asking that you forward them the information for the survey.