The purpose of this study is to explore the effectiveness of <i>Gamchobunmil-tang</i> as a treatment for early dumping syndrome. A patient reported abdominal pain after eating, was not able to eat more than two spoons of thin rice gruel, and had lost 8 kg of his weight. The patient was treated with <i>Gamchobunmil-tang</i> three times a day for 12 days. The effects of the treatment were evaluated using the Visual Analogue Scale and the amount and form of the patient’s intake. After treatment, the pain due to the dumping syndrome decreased. The Visual Analogue Scale score dropped significantly from 9 to 2, and increased amounts and novel forms of the food the patient consumed were observed. Despite the lack of a case, the results showed that <i>Gamchobunmil-tang</i> was effective in reducing the pain caused by the early dumping syndrome. Further research might prove that <i>Gamchobunmil-tang</i> could be an alternative treatment method for early dumping syndrome.