In study 1, there was no significant difference in age, sex, BMI, history of diverticular bleeding, history of diverticulitis, drinking, smoking, complications, NSAIDs, antiplatelet drugs, laboratory data of Hb, and endoscopic hemostasis between the patients with and without recurrence in the burdock tea-treated group. This evidence concerns the gene GSTM1 and Colonic diverticula.