To evaluate the clinical necessity of postoperative gastrointestinal decompression after operation on lower digestive tract.Three hundred and sixty-eight patients who required excision and anastomosis of lower digestive tract were randomly divided into two groups, with or without receiving gastrointestinal decompression after operation. Clinical therapeutic efficacy and complications were compared between two groups.The volume of gastrointestinal suction ranged from 10 ml to 520 ml each day after operation, and was less on the first day than those on the second and the third day after operation in decompression group. There was no significant difference in the average girth between two groups before and after operation. The average girths were shorter before operation than those after operation in two groups (P 0.05). The complication rate was significantly higher in decompression group than that in non-decompression group (28% vs. 8.2%, P< 0.001). The incidence of pharyngolaryngitis was up to 23.1% in decompression group. There was no difference in hospital stay between the two groups after operation.The recovery of patients who receive excision and anastomosis of lower digestive tract will benefit from non-gastrointestinal decompression.