Decreased masticatory function may cause gastrointestinal symptoms, leading to appetite loss. This study aimed to elucidate the relationship between oral health status and gastrointestinal symptoms. Two hundred and fifty-six Japanese subjects completed a questionnaire including the General Oral Health Assessment Index and Izumo scale, as well as provided data regarding gender, age, body mass index, daily brushing frequency, denture use, presence of family dentist, dental visits in the past year, alcohol consumption, smoking status, and hours of sleep. Significant differences were found in terms of gender, age, brushing frequency per day, hours of sleep, and the Izumo scale（ reflux, pain, fullness, constipation, diarrhea）. No significant differences in the other variables were found between the two groups. Multivariate analysis showed a significant correlation of the General Oral Health Assessment Index score with diarrhea. Overall, poor oral health-related quality of life may increase the likelihood of experiencing diarrhea.