Primary eosinophilic gastrointestinal disease (EGID) is a rare inflammatory gastrointestinal disorder characterized by eosinophil infiltration in the gut. EGIDs are sub-grouped as eosinophilic esophagitis (EE), eosinophilic gastroenteritis (EG), and eosinophilic colitis (EC). The least frequent manifestation of EGIDs is EC which affects newborns and young adults. An 18-year-old male patient was admitted complaining of recurrent epigastric and lower abdominal pain, abdominal distension, vomiting, bloody diarrhea, and weight loss for a long time. Laboratory investigations performed showed a white blood cell (WBC) count of 14.5 109/L, with 62.1% neutrophils, 22.4% lymphocytes, 13.2% monocytes, 28.2% eosinophils, 0.1% basophils, and hemoglobin (HGB) level of 6.3 g/dL. Stool examination was positive in the helicobacter pylori test and occult blood. Colonoscopic biopsy showed active colitis with eosinophilia. We recommended corticosteroid treatment to the patient. With prednisolone treatment of 20 mg 2 times per day, the clinical features resolved.