Objective:To compare the results of high-resolution colonic manometry (HRCM) in patients with four subtypes of constipation: slow transit constipation(STC), outlet obstruction constipation (OOC), mixed STC and OOC, and normal transit constipation(NTC), and to explore the intestinal motility characteristics of patients with different subtypes of constipation.Methods:From 20th January 2017 to 20th September 2020, the HRCM results of 225 patients with functional constipation who visited the Department of Anorectal Surgery of Tianjin Union Medical Center were retrospectively analyzed. According to the results of colonic transit test, 225 patients were divided into STC group (108 cases), OOC group (36 cases), mixed group (28 cases) and NTC group (53 cases). General information such as Wexner constipation scores, clinical symptoms (decreased desire to defecate, sensation of anorectal blockage, hand-assisted defecation, spontaneous bowel movements frequency<3 times per week), the incidence, frequency within one day (hereinafter referred to as frequency), average velocity, average wave amplitude, average duration of contraction, average length of contraction, and the dynamic index (DI) of average pressure of high-amplitude propagating contraction (HAPC), as well as the frequency, average wave amplitude, average duration of contraction, and the DI of average pressure of low-amplitude propagating contraction (LAPC) were compared among the four groups. One-way ANOVA and multiple comparison, Kruskal-Wallis test and chi-square test were used for statistical analysis.Results:The Wexner constipation scores of the STC, OOC, mixed and NTC group were 13.17±4.04, 13.97±4.55, 11.36±4.03 and 11.58±4.06, respectively, and the difference was statistically significant ( F=3.879, P<0.05). The Wexner consipation scores of the STC and OOC group were both higher than the mixed and NTC group, and the difference were statistically significant (One-way ANOVA and multiple comparison, all P<0.05). The proportion of decreased desire to defecate, sensation of anorectal blockage, hand-assisted defecation, spontaneous bowel movements frequency<3 times per week of STC, OOC, mixed and NTC group were 47.2% (51/108), 36.1% (13/36), 14.3% (4/28), 20.8% (11/53); 42.6% (46/108), 75.0% (27/36), 46.4% (13/28), 64.2% (34/ 53); 31.5% (34/108), 38.9% (14/36), 3.6% (1/28), 18.9% (10/53); 90.7% (98/108), 77.8% (28/36), 82.1% (23/28) and 62.3% (33/53), and the differences were statistically significant ( χ2=17.093, 12.463, 13.437 and 18.927; all P<0.01). The proportion of decreased desire to defecate of STC group was higher than that of mixed and NTC group, and spontaneous bowel movements frequency<3 times per week was higher than that of OOC and NTC group, and the differences were statistically significant ( χ2=10.014, 10.518, 4.418 and 19.016; all P<0.05). The proportion of sensation of anorectal blockage of OOC group was higher than that of STC and mixed group, and the proportion of hand-assisted defecation was higher than that of the mixed and NTC group, and the differences were statistically significant ( χ2= 9.511, 5.486, 10.948 and 4.363, all P<0.05). The incidence of HAPC in STC, OOC, mixed and NTC groups was 39.8% (43/108), 36.1% (13/36), 57.1% (16/28), and 60.4% (32/53), respectively, and the difference was statistically significant ( χ2=8.880, P=0.031). The incidence of HAPC in STC group and OOC group were lower than that of NTC group, and the differences were statistically significant ( χ2=6.041 and 5.050, P=0.014 and 0.025). There were no statistically significant difference in the frequency, average velocity, average amplitude, average duration of contraction, average length of contraction and DI of pressure of HAPC in four groups, and there were no statistically significant difference in the frequency, average amplitude, average duration of contraction, and DI of pressure of LAPC in the four groups (all P>0.05). Conclusions:Doctors can more clearly and objectively observe the intestinal motility characteristics of patients with different subtypes of constipation through HRCM. HRCM provides a strong basis for the diagnosis and further treatment of functional constipation, and has a high clinical application value.

Objective: To investigate the incidence, molecular features and clinical significance of RNA splicing machinery genes mutation in myelodysplastic syndromes (MDS) and related diseases. Methods: Mutational analysis of splicing factor 3B subunit 1 (SF3B1) (K700E) , U2 small nuclear RNA auxiliary factor 1 (U2AF1) (S34, Q157P) and serine/arginine-rich splicing factor 2 (SRSF2) (P95) in 118, de novo MDS and related diseases were separately performed by using polymerase chain reaction (PCR) followed by sequence analysis. Results: Of 118 MDS patients, 76 males and 42 females, the median age was 53.5 (13-84) years old. 19.49% (23/118) had SF3B1 (K700E) mutation. As compared with those with wild type SF3B1, patients with SF3B1 K700E were of older[58 (32-78) years vs 51 (13-84) years, z=-1.981, P=0.048], lower HGB level[63 (40-95) g/L vs 77 (34-144) g/L, z=-3.192, P=0.001], higher platelet counts[121 (22-888) ×10⁹/L vs 59 (6-1 561) ×10⁹/L, z=-3.305, P=0.001], lower bone marrow blast cell counts[0.007 (0-0.122) vs 0.017 (0-0.268) , z=-2.885, P=0.004], higher ring sideroblasts percent [0 (0-64%) vs 0 (0-58%) , z=-4.664, P<0.001]. Of 105 MDS patients, 21.9% had U2AF1 (S34, Q157P) mutations. Of 107 MDS patients, 8 patients (7.48%) had SRSF2 (P95) mutations. Patients with SRSF2 mutations were older at diagnosis, the median age was 63 (50-84) years old, including 4 cases RAEB-1. The ratio of mutation was 14.29% (4/28) , and three patients transformed to AML. SF3B1 K700E and SRSF2 P95H mutations coexisted in 1 patient, and SF3B1 K700E and U2AF1 S34Y mutations were found concomitantly in 2 patients. Conclusion Only SF3B1 gene mutation was closely related to ring sideroblasts, it was the key to pathogenesis of MDS.