Abstract： Objective： To observe the clinical effect of Yiqi Qingre Jiedu Decoction combined with Montmorillonite Powder for diarrhea after operation for rectal cancer. Methods： A total of 96 cases of patients with diarrhea after operation for rectal cancer were divided into the observation group and the control group according to the random number table method， with 48 cases in each group. The control group was given the oral administration of Montmorillonite Powder， and the observation group was additionally treated with self-made Yiqi Qingre Jiudu Decoction based on the treatment of the control group. After 14 days of treatment，the clinical effects and the incidences of adverse reactions in the two groups were observed and compared. Before and after treatment， the levels of serum stress response indexes including C- reactive protein (CRP)， interleukin- 6 (IL- 6)， interleukin- 8 (IL- 8)， superoxide dismutase (SOD) and malondialdehyde (MDA) as well as visceral protein indexes including prealbumin (PA) and transferrin (TRF) in the two groups were compared. Results：The total effective rate of clinical effect was 95.83% in the observation group， higher than that of 75.00% in the control group， the difference being significant (P＜0.05). After treatment，the levels of CRP，IL-6 and IL-8 in serum and plasma MDA in the two groups were decreased when compared with those before treatment (P＜0.05)， and all the above indexes in the observation group were lower than those in the control group (P＜0.05). The levels of plasma SOD in the two groups were increased when compared with those before treatment (P＜0.05)， and the level in the observation group was higher than that in the control group (P＜0.05). After treatment， the levels of PA and TRF in the two groups were increased when compared with those before treatment (P＜ 0.05)，and the above two indexes in the observation group were higher than those in the control group (P＜ 0.05). During treatment，the incidence of adverse reactions was 4.17% in the observation group and 6.25% in the control group，there being no significant difference between the two groups (P＞0.05). Conclusion： The therapy of Yiqi Qingre Jiedu Decoction combined with Montmorillonite Powder for diarrhea after operation for rectal cancer can enhance the clinical effect，reduce body stress response and inflammatory response and improve the level of visceral protein，with good safety.