ObjectiveTo study the curative effect and postoperative anorectal dynamics change of tissue-selecting therapy stapler (TST) and procedure for prolapse and hemorrhoids (PPH) respectively combined with mixed Milligan-Morgan and lauromacrgol injection in the treatment of Ⅲ–Ⅳ degree mixed hemorrhoid.MethodsClinical data of 158 patients with Ⅲ–Ⅳdegree mixed hemorrhoid who received operation in the Department of Colorectal and Anal Surgery, Chaoyang Central Hospital, from May 2016 to March 2018 were analyzed retrospectively, the observation group (TST+Milligan-Morgan+lauromacrgol injection, 80 cases) and control group (PPH+Milligan-Morgan+lauromacrgol injection, 78 cases). The clinical efficacy, adverse reactions, postoperative complications and recurrence of the two groups were observed, and the changes of anorectal dynamic indexes before and after operation were observed.ResultsPostoperative symptoms of mixed hemorrhoid prolapse could be alleviated by 100% in both the observation group and the control group, and the relief rate of hematochezia was 93.8% and 92.3%, respectively, and the effective rate of 1 year after surgery was 97.5% and 94.9%, respectively. Comparison between the two groups showed no statistical difference (P>0.05). The operative time, intraoperative blood loss, VAS pain score and hospital stay of the observation group were all better than those of the control group (P<0.05). In terms of postoperative massive hemorrhage and anastomotic stenosis, although the incidence rate of the control group was higher than that of the observation group (3.8% vs. 1.3% and 2.6% vs. 0.0%, respectively), there was no statistical significance in the two groups (P>0.05). Postoperative anal drop, stool urgency, postoperative urinary retention and postoperative stimulation of anal papilla hypertrophy and proliferation complications were significantly better in the observation group than in the control group (P<0.05). The difference of maximum anal systolic pressure (MASP) in the two groups of patients between before and after surgery and the comparison of MASP results between the two groups after surgery showed no statistical differences (P>0.05). The differences of resting anal sphincter pressure (RASP) and rectal sensory threshold volume (RSTV) between before and after operation were not statistically significant (P>0.05). The difference of rectal maximum threshold volume (RMTV) value and the comparison of RASP, RSTV and RMTV value between the two groups after surgery showed that the observation group were superior to the control group and the differences were statistically significant (P<0.05).ConclusionsTST or PPH combined with Milligan-Morgan and lauromacrgol injection both are effective and minimally invasive methods for the treatment of Ⅲ–Ⅳ degree mixed hemorrhoid. However, the observation group has shorter operative time and hospital stay, less intraoperative blood loss, and lower postoperative pain score. What is more important is that the postoperative complications are less and the anal function is protected to the maximum extent, and the quality of life of patients after operation is greatly improved.