Objective:To evaluate the efficacy and safety of topical delivery of modified Da-Cheng-Qi Decoction(加味大承气汤,MDCQD) by low-frequency ultrasound sonophoresis (LFUS) in patients with refractory metastatic malignant bowel obstruction (MBO) using an objective performance criteria (OPC)design.Methods:Fifty patients with refractory metastatic MBO were enrolled in this open-label single-arm clinical trial.Alongside fasting,gastrointestinal decompression,glycerol enema,intravenous nutrition and antisecretory therapy,a 50 g dose of MDCQD (prepared as a hydrogel) was applied through topical delivery at the site of abodminal pain or Tianshu (S 25) using LFUS for 30 min,twice daily for 5 consecutive days.The overall outcomes were the remission of intestinal obstruction,improvement on abdominal pain,abdominal distention,nausea and vomiting scores.Indicators of safety evaluation included liver and renal function as well as blood coagulation indicators.Results:Among 50 patients,5 patients (10％) showed complete remission of intestinal obstruction and 21 patients (42％) showed improvement of intestinal obstruction.The overall remission rate of bowel obstruction was 52％.The results of the symptom score,based on the severity and frequency of the episode,were as follows:26 patients (52％) showed improvment on symptom scores,20 patients (40％) did not respond to treatment,and 4 patients (8％) discontinued treatment due to intolerance.No serious adverse effects or abnormal changes on liver and renal functions or blood coagulation were observed.Conclusion:Topical delivery of MDCQD at 100 g/day using LFUS can improve the treatment response in patients with refractory metastatic MBO.