Background: There are several benign, many spindle cells involving the mucosa and /or submucosa in the gut. These include perineurioma, Schwann cell hamartomas, ganglioneuromas, leiomyomas, inflammatory fibrous polyps, granular cell tumors, and benign unclassified mucosal polyps (BUMPs). Results: We report the multiple BUMPs of the colorectum. A 61-year-old woman performed the colonic fiber, because of the following-up of a gastrointestinal stromal tumor (GIST). The biopsy, cold snare polypectomy, and endoscopic mucosal resection of the colon or rectum were done. Histologically, these lesions were the proliferation of plump, uniform spindle cells with eosinophilic cytoplasm, indistinct cell borders, and bland nuclei without mitoses. Immunohistochemically, the tumor cells were positive for vimentin, but negative for epithelial membranous antigen (EMA), S-100, a-smooth muscle actin (a-SMA), Desmin, GLUT-1, Claudin-1, and type IV collagen. Conclusion: The BUMPs may be the most common mesenchymal polyps. This is a “wastebasket” designation. There are no multiple BUMPs of the colorectum in the English literature. The phenomenon may be related to some syndrome.