The effects of lactic acid fermented yam yogurt (Yam/YG) on colon mucosal tissue were investigated in a loperamide-induced constipation rat models. Sprague-Dawley rats were fed for 6 weeks with 3 types of diets (normal, supplemented with lactic acid bacteria, and supplemented with Yam/YG), and were then administered loperamide intraperitoneally twice daily for 5 days. Administration of loperamide decreased fecal excretion and the moisture content of feces with increasing of numbers of pellets in the colon. On the histopathologic findings from hematoxylin and eosin (H& E) and alcian blue stainings, supplementation with Yam/YG resulted in the recovery of depleted goblet cells and mucin, and increased the numbers of Ki-67 positive cells, indicating restoration of colonic mucosa through cell proliferation and crypt regeneration against damages observed in crypt epithelial cells of loperamide-induced rats. These results indicate that Yam/YG improves evacuation and mucus production in the gastrointestinal tracts of constipated-induced rats.