Objective To investigate the influence of preoperative enteral nutrition with dietary fiber on the nutritional status of patients with colon colostomy diaplasis, and discuss its safety. Methods Forty preoperative colon colostomy diaplasis patients from West China Hospital treated between September 2013 and June 2014 were randomly assigned into trial group and control group with 20 in each. The baseline of the two groups was the same (all P > 0.05). The trial group was given enteral nutrition with dietary fiber before operation for seven days, while control group was given homogenate diet with equal quantity of energy and nitrogen content for the same period of time. All patients were being tested for nutritional indexes on the day of admission and on the fifth day after surgery. Meanwhile, other indexes such as the first time of flatus and defecation, abdominal distension, bellyache, and other adverse reactions were recorded too. Results There was no statistical difference in nutritional indexes on the day of admission and on the fifth day after surgery between two groups (P > 0.05). Patients with dietary fiber had significantly higher incidence of abdominal distension than the control subjects (P < 0.05), but other adverse reactions had no statistical differences between the two groups (P > 0.05). No anastomotic leakage occurred in both the two groups. Patients with dietary fiber had significantly earlier time of flatus than the control group (P < 0.05). Patients with dietary fiber had significantly lower incidence of diarrhea than the control subjects (P < 0.05). Conclusions The study suggests that it is safe and feasible to use enteral nutrition with dietary fiber for preoperative colon colostomy diaplasis patients. Using dietary fiber is helpful for intestinal function recovery and reduction of the occurrence of adverse reactions after surgery.