After the stress of traveling what a terrible experience; being sick away from home is worse yet.

As others have said, the onset of symptoms for food borne illness can be anywhere from five or six hours for staph to 45 days for hepatitis. The most common range starts at about 24 hours, not sure how that fits in the chronology of the OP's situation but might be a starting point to backtrack. There could well be multiple cases of illness confirming a food borne illness but with a source the OP may not have considered.