Abstract

Aim of the Study:

To observe the efficacy and safety of CQE in rapidly alleviating inflammatory activity in UC.

Materials and Methods:

CQE extracts were analyzed by UHPLC–Q Exactive Orbitrap–HRMS. This study used a self-controlled design before and after treatment. A total of 114 UC patients were included and treated with traditional rectal enema administration of CQE. Among them, 107 patients completed the treatment, and 101 patients with complete clinical and laboratory data were included in the final analysis. The primary clinical intestinal symptoms, mucosal endoscopic and pathological changes, laboratory indicators, quality of life scores, and adverse reactions were compared before and after 14 days of enema treatment. A historical comparison was made with previous studies. The expression of intestinal tight junction proteins in the colons of UC patients during active periods was detected using Quantitative Real-time PCR (RT-qPCR) and Western blot (WB).

Results:

The main compounds in CQE were identified, including Gallic acid, Matrine, Oxysophocarpine, Ellagic acid, Prim-O-glucosylcimifugin, Cytisinicline, Danshensu, Protocatechuic acid, Cimifugin, Salvianolic acid A Cytisinicline, Indigo, Indirubin, Tryptanthrin and others. The primary endpoint, defined as the change in modified Mayo score, showed a significant improvement after 14 days of CQE treatment (P < 0.001). The clinical response rate was 94.06% (95/101), and the clinical remission rate was 66.34% (67/101). The endoscopic mucosal healing rate was 76.24% (77/101), and the histological remission rate was 38.61% (39/101). Compared to before treatment, post-treatment scores for clinical intestinal symptoms, Mayo endoscopic scores (MES), Geboes index, fecal calprotectin (FC), and fecal occult blood test (OB) were significantly reduced (P < 0.001). The UCEIS score for the distal rectum and sigmoid colon showed more improvement than the proximal colon (P < 0.01). Hemoglobin (HGB), albumin (ALB), and quality of life scores increased (P < 0.05), while liver and kidney function indicators showed no abnormal elevations after treatment (P < 0.05). Compared to historical data from previous studies using steroids and biologics, CQE significantly improved clinical and endoscopic remission rates. RT-qPCR and WB results demonstrated that the herbal enema helps repair the intestinal mucosal barrier in UC patients.

Conclusion:

CQE can rapidly alleviate inflammatory activity in UC within 14 days and improve patients’ quality of life, with a low incidence of adverse events.

1 Introduction

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon, characterized by recurrent episodes of inflammation and remission, with mucosal inflammation typically starting from the rectum and extending to the proximal segments of the colon. UC’s inflammatory activity manifests through symptoms such as diarrhea, mucus or bloody pus in the stool, and abdominal pain, which cause significant discomfort to patients. Therefore, quickly alleviating inflammatory symptoms and improving patients’ wellbeing and compliance is of great importance (Raine et al., 2022). Epidemiological studies in the early 21st century suggest that the incidence of UC in Asia may be rapidly increasing, particularly in China, where the incidence rate has risen sharply in the past decade (Ng et al., 2017).

To reduce disease activity and maintain stable remission, it is essential to find a new treatment method that is rapid, effective, and safe for UC. In China, TCM has been widely used to treat UC. Researches indicate that from 1981 to 2000, over 20% of UC patients used simple Chinese medicine treatment, while 59.1% adopted a combination of TCM and Western medicine (Jiang and Cui, 2002). Common TCM treatment methods include oral and local administration, with rectal enemas and suppositories being the primary means of local treatment, and rectal enemas playing a significant role in UC treatment (Chen et al., 2005). Currently, most evaluations of the efficacy of TCM enemas in treating UC are conducted over extended periods, usually after 1 month or even 6 months of treatment. Few clinical studies focus on the rapid relief of inflammatory activity, hindering the assessment of whether TCM enemas can achieve quick symptom relief. Therefore, research aimed at rapid relief of inflammatory activity is urgently needed. Additionally, many clinical studies on TCM treatment for UC involve the combination of TCM with other medications, making it difficult to independently assess the efficacy of TCM. CQE, developed from long-term clinical practice, is a TCM formula composed of 12 herbs, including Indigo Naturalis (Qingdai powder), Portulaca oleracea (Ma Chi Xian), Patrinia scabiosaefolia (Bai Jiang Cao), and Sophora flavescens (Ku Shen). Our previous research demonstrated that CQE can rapidly improve clinical symptoms in patients with UC. Most patients receiving CQE showed marked improvements in stool frequency, rectal bleeding, and abdominal pain within 1–2 weeks. Moreover, achieving therapeutic targets within a 2-week course significantly enhanced patient adherence, better reflecting the concept of rapid symptom relief (Wetwittayakhlang et al., 2021). Therefore, a 14-day period was selected based on both clinical practice and pharmacodynamic considerations and determined to be appropriate to evaluate the rapid anti-inflammatory and symptom-relieving effects of CQE. In addition, there is a significant correlation between achieving clinical remission (based on symptoms/score indicators) within 2 weeks and improvement in endoscopic/tissue conditions within 8 weeks (Solitano et al., 2025; Chen et al., 2024). A 14-day evaluation window can effectively reflect early efficacy while minimizing the influence of spontaneous remission or other confounding factors. Meanwhile, this relatively short observation period ensures safety monitoring and avoids long-term confounders from concurrent medications or dietary factors (Loftus et al., 2023). This study, with a 14-day treatment period, aimed to evaluate the efficacy of CQE in rapidly alleviating UC inflammation. The results indicate that CQE provides rapid relief of inflammatory activity in UC and achieves remission without steroid intervention.

2 Materials and methods2.1 Study design

This was a single-center, single-arm clinical study with Objective Performance Criteria (OPC), employing a prospective self-controlled design before and after treatment. Patients were recruited from the Department of Gastroenterology at the First Affiliated Hospital of Zhejiang Chinese Medical University between May 2019 and December 2023. The study was conducted in accordance with the Declaration of Helsinki and was approved by the Ethics Committee of the First Affiliated Hospital of Zhejiang Chinese Medical University (No. 2018-ZX-025-01). The study was also registered on the International Traditional Medicine Clinical Trial Registry platform (http://itmctr.ccebtcm.org.cn/, NO.: ITMCTR2025000610). Written informed consent was obtained from all participants prior to enrollment, and written consent was also obtained for the collection of clinical samples.

The study was designed in collaboration between the sponsor (the First Affiliated Hospital of Zhejiang Chinese Medical University) and gastroenterologists. Data management and statistical analysis were conducted by a third-party institution. The sponsor collected the data, monitored the study’s progress, and coordinated the manuscript preparation with all authors. All authors had access to the study data and reviewed and approved the final manuscript.

2.2 Study population

Based on the Montreal classification, the disease extent was classified into ulcerative proctitis (E1), left-sided UC (E2), and extensive UC (E3) (Satsangi et al., 2006); The severity was categorized as mild, moderate, or severe according to the modified Truelove and Witts classification (Truelove and Witts, 1955). Patients were also categorized by clinical type as initial onset or chronic relapsing (Magro et al., 2017).

2.2.1 Inclusion criteria

① According to the 2017 ECCO Consensus on the Diagnosis and Management of Inflammatory Bowel Disease, the patient was diagnosed with active ulcerative colitis (Magro et al., 2017); ② Age between 18 and 80 years at the time of informed consent; ③ Diagnosed as extensive UC through colonoscopy and other diagnostic tests; ④ Diagnosis of the TCM syndrome of damp-heat in the large intestine, with symptoms such as diarrhea, mucus, or bloody pus in the stool, abdominal pain, tenesmus, a burning sensation in the anus, bloating, dark urine, dry mouth, and bitter taste. TCM signs included a red tongue, yellow greasy coating, and slippery pulse; ⑤ Signed informed consent.

2.2.2 Exclusion criteria

① Inability to undergo colonoscopy or difficulty tolerating enema administration; ② Presence of serious comorbidities such as hematological, cardiovascular, hepatic, renal, or neurological diseases or psychological disorders; ③ Complications such as toxic megacolon; ④ Participation in another clinical studies within the last three months; ⑤ Unstable or severe disease requiring urgent medical intervention; ⑥ Documented allergy or hypersensitivity to any component of the CQE preparation; ⑦ Abnormal liver or renal function at baseline; ⑧ Concurrent use of systemic corticosteroids, immunosuppressants, or biologic agents during the study period.

2.2.3 Dropout criteria

① Use of medications or interventions that could potentially influence study outcomes or interfere with the assigned treatment protocol; ② Failure to complete the prescribed treatment course or alteration of the treatment regimen without authorization; ③ Development of severe complications, new comorbidities, or significant physiological changes rendering continued participation unsafe or inappropriate; ④ Inability to attend scheduled follow-up visits or loss to follow-up, regardless of whether formal withdrawal was declared.

2.2.4 Safety assessment

An a priori safety assessment of the CQE formulation was conducted based on existing pharmacological and clinical literature. Known adverse effects, potential herb–drug interactions, and contraindications of each botanical component were reviewed prior to study initiation. All patients were closely monitored for adverse events throughout the intervention, and routine laboratory parameters, including liver and renal function, were assessed before and after treatment.

2.3 Sample size

The sample size was calculated based on the primary endpoint, defined as the change in modified Mayo score. Based on the sample size calculation formula: n = [σ(Z1-α/2 + Z1-β)/(μ-μ0)]2, and using preliminary trial results, the primary outcome measure was the modified Mayo score, with a pre-treatment score of (8.20 ± 3.27) and a post-treatment score of (6.20 ± 3.90). With α = 0.05 and β = 0.1, it was calculated that 40 patients were needed. Considering a 20% dropout rate, the study aimed to recruit at least 48 patients. In this prospective single-arm study, all eligible consecutive patients during the study period were included to enhance the statistical precision and generalizability of the findings. As a result, a total of 114 patients were ultimately enrolled, exceeding the minimum required sample size. The additional outcomes assessed in this study were considered secondary endpoints and were not used for sample size determination.

2.4 Study medication and preparation

CQE consisted of 12 Chinese herbal medicine: 3 g of Qing Dai powder, 30 g of Ma Chi Xian, 15 g of Bai Jiang Cao, 15 g of Ku Shen, 10 g of Shi Liu Pi, 6 g of Er Cha, 30 g of Di Yu, 10 g of Dan Shen, 10 g of Fang Feng, 6 g of Wu Bei Zi, 9 g of Sheng Ma and 15 g of Wu Mei. The botanical origins of all herbs are shown below (Table 1). The CQE was prepared and quality controlled by the Pharmacy Center of the First Affiliated Hospital of Zhejiang Chinese Medical University in accordance with standardized hospital decoction procedures and the Chinese Pharmacopoeia. All herbal materials were weighed according to the original prescription ratio, soaked in water at a 10-fold ratio for 30 min, and decocted twice (30 min for the first extraction and 20 min for the second extraction). The extracts were combined, filtered, and concentrated under reduced pressure to yield a final preparation equivalent to approximately 0.49 g/mL of crude drug. The decoction was administered orally at a dose of 200 mL per administration, twice daily. This preparation procedure was used exclusively for clinical administration and is distinct from the sample preparation method employed for LC–MS analysis.

Chinese nameFull namePart usedWeight (g)Qing DaiIndigo naturalisFoliage3Ma Chi XianPortulaca oleracea LHerb30Bai Jiang CaoPatrinia scabra BungeHerb15Ku ShenSophora flavescens AitonRoot15Shi Liu PiPunica granatum LPericarp30Er ChaAcacia catechu (L.f.) WilldBranch6Di YuSanguisorba officinalis LRoot30Dan ShenSalvia miltiorrhiza BungeRoot10Fang FengSaposhnikovia divaricata (Turcz.) SchischkRoot9Wu Bei ZiRhus chinensis MillLeaf6Sheng MaActaea cimicifuga LRoot9Wu MeiPrunus mume (Siebold) Siebold & ZuccKernel15

Components of the CQE, the plant name has been checked with http://www.theplantlist.org.

All botanical drugs used in the CQE preparation are officially listed in the Chinese Pharmacopoeia and are not derived from endangered or protected species. The raw materials were sourced from certified suppliers in compliance with national regulations on medicinal plant use. None of the ingredients are classified as restricted substances, and all materials were obtained through ethical and sustainable channels.

2.5 UHPLC–Q exactive orbitrap–HRMS analysis

The herbs of the CQE were mixed in accordance with the original prescription dosage ratios. All twelve herbs were soaked in deionized water in proportion for 1 hour. Subsequently, water equal to ten times the weight of the ingredients was added, and the mixture was boiled for an additional 30 min. After decoction and filtration, the filtrate was concentrated to a 1.0 g/mL density, which was used as the stock solution for analysis. The sample was mixed and subjected to ultrasonic extraction in an ice-water bath, followed by low-temperature precipitation and centrifugation. The resulting supernatant was collected, spiked with an internal standard, and transferred to vials for subsequent analysis. The preparation procedure described for LC-MS analysis was performed solely for chemical profiling.

The metabolomic data analysis was performed by Shanghai Luming biological technology co., LTD (Shanghai, China). An ACQUITY UPLC I-Class plus (Waters Corporation, Milford, USA) fitted with Q-Exactive HF mass spectrometer equipped with heated electrospray ionization (ESI) source (Thermo Fisher Scientific, Waltham, MA, USA) was used to analyze the metabolic profiling in both ESI positive and ESI negative ion modes. Chromatographic separation was performed on an ACQUITY UPLC HSS T3 column (1.8 μm, 2.1 × 100 mm) using a water–acetonitrile mobile phase with gradient elution. The flow rate was 0.35 mL/min and column temperature was 45 °C. All the samples were kept at 4 °C during the analysis. The injection volume was 2 μL. Mass spectrometry data were acquired over a scan range of m/z 100–1,500 with data-dependent MS/MS acquisition.

2.6 Data preprocessing and statistical analysis

The original LC-MS data were processed by software XCMS V4.5.1 for baseline filtering, peak identification, integral, retention time correction, peak alignment, and normalization. Main parameters of 5 ppm precursor tolerance, 20 ppm product tolerance. The extracted features were subsequently matched against an in-house database (LuMet-TCM, LuMet Biotechnology Co., Ltd., Shanghai, China), which has been utilized in previous LC–MS-based analyses of herbal medicines (Lu et al., 2025; Pan et al., 2024), and the publicly available HERB database (http://tcmspw.com/herb.php) for compound annotation. Compound identification was based on accurate mass-to-charge ratios (m/z), MS/MS fragmentation patterns, and isotopic distribution.

Compounds were tentatively identified based on XCMS-processed features, and only those with a total matching score greater than 40 were retained for further analysis. After merging and weighting the substances in the positive and negative ion mode, the total content of the relative peak area of the metabolites is set at 100% to obtain a qualitative and quantitative result data matrix, the matrix contains all the information extracted from the original data that can be used for analysis, and subsequent analysis is based on it. Draw an EIC diagram and an MS2 mirror comparison diagram with secondary fragment structure annotations for each identified traditional Chinese medicine ingredient. Draw a pie chart based on the quantity of all identified traditional Chinese medicine components under each chemical classification category.

2.7 Administration method

For patients with active UC, treatment was administered via rectal enema without the combination of other medications, using CQE for 14 consecutive days. During enema administration, patients were placed in a left lateral position with their hips elevated. After lubricating the enema tube with paraffin oil, the tube was inserted 15 cm into the rectum. A 50 mL syringe with a soft tube was used to inject the enema solution into the rectum, followed by a 20 mL saline flush. The enema was administered twice a day, once in the morning and once in the evening, with the evening enema retained overnight.

2.8 Efficacy evaluation methods

The primary endpoint of this study was defined as the change in modified Mayo score after treatment. Secondary endpoints included clinical symptom scores (SCCAI), endoscopic scores (MES), histopathological scores (Geboes), inflammatory biomarkers (FC, OB, CRP, ESR, WBC, PLT), nutritional indicators (HGB, ALB), quality of life (IBDQ).

2.8.1 Clinical intestinal symptom evaluation

Clinical symptoms (Bowel frequency (day and night), Blood in stool, Urgency of defecation, General wellbeing, Extracolonic features) will be assessed using the Simple Clinical Colitis Activity Index (SCCAI) a validated and widely used clinical index for the assessment of disease activity in UC (Walmsley et al., 1998; Kishi et al., 2022). The total SCCAI score ranges from 0 to 19, with higher scores indicating greater disease activity. Patients’ clinical intestinal symptoms were recorded daily. The SCCAI was assessed at baseline and at predefined follow-up visits (day 4 and day 14) to evaluate changes in clinical disease activity. A SCCAI score of <2.5 was predefined as the threshold for clinical symptom remission (Higgins et al., 2005).

2.8.2 Disease severity assessment

Disease Severity Scoring: Disease severity was scored using the modified Mayo Score for UC before and after enema treatment. Scores were based on the patient’s daily bowel movements, rectal bleeding, colonoscopic findings, and the physician’s overall assessment. The scoring was conducted by a UC specialist physician. Due to the single-arm design, blinding to treatment status was not feasible. However, clinical data were recorded prospectively, and scoring was performed using predefined criteria by experienced clinicians to reduce subjective bias. Mild disease activity was defined as a score between 3-5, moderate activity as 6–10, and severe activity as 11–12 (D'Haens et al., 2007).

Disease Severity Improvement Assessment: Clinical remission was defined as a Mayo score ≤2 with no individual item scoring >1. Clinical response was defined as a ≥30% reduction from baseline Mayo score and a decrease of ≥3 points, with a reduction of ≥1 point in rectal bleeding or a rectal bleeding score of 0 or 1. Clinical remission rate (%) = (number of cases in clinical remission/total cases) × 100%. Clinical response rate (%) = (number of clinically effective cases/total cases) × 100%.

2.8.3 Endoscopic and histopathological scoring

Endoscopic Scoring: Mayo endoscopic scores (MES) were recorded before and after treatment, with scoring based on the most severely affected part of the colon as observed through colonoscopy. The MES is widely used for the evaluation of mucosal inflammation and disease activity in UC. Recent studies have further validated its reliability and clinical utility in assessing treatment response (Khanna et al., 2022; Xu et al., 2022). Endoscopic scoring was performed by experienced endoscopists. Blinding to treatment time point was not implemented; however, evaluations were conducted according to standardized scoring criteria, and consistency was maintained across assessments to minimize inter-observer variability. Mucosal healing was defined as an MES score of 0 or 1. Mucosal healing rate (%) = (number of cases with mucosal healing/total cases) × 100% (Schroeder et al., 1987).

Histopathological Scoring: Biopsy samples were taken from the most severely affected areas before and after treatment. If a patient showed improvement, biopsy sites remained consistent pre- and post-treatment. A single pathologist evaluated the mucosal samples according to the Geboes scoring system. The pathologist was not blinded to the treatment time point; however, all samples were assessed using predefined histological criteria, and evaluations were performed in a consistent manner to reduce subjective bias. Histological remission was defined as a Geboes score <2. Histological remission rate (%) = (number of cases with histological remission/total cases) × 100% (Geboes et al., 2000).

2.8.4 Stratified analysis

By Disease Severity: Patients were grouped into mild, moderate, and severe categories based on disease severity scores, and their improvement, as well as endoscopic scores, were analyzed.

By Disease Extent: Patients were grouped based on disease extent into E1, E2, and E3 categories according to the Montreal classification. Disease severity improvement and endoscopic scores were analyzed for each group.

2.8.5 Inflammation and nutritional markers evaluation

Patients underwent laboratory tests before and after treatment.

Inflammatory Markers: White blood cell count (WBC), platelet count (PLT), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), FC, and OB. The scoring method for OB was as follows: OB (−) = 0 point, OB (1+) = 1 point, OB (2+) = 2 points, OB (3+) = 3 points.

Nutritional Markers: HGB and ALB.

2.8.6 Quality of life assessment

Patients’ quality of life was assessed using the Inflammatory Bowel Disease Questionnaire (IBDQ), which includes sections on intestinal symptoms, systemic symptoms, emotional function, and social function. A higher score indicated a better quality of life (Guyatt et al., 1989).

2.8.7 Safety indicators

Patients were monitored for safety indicators before and after treatment. These included alanine aminotransferase (ALT), aspartate aminotransferase (AST), and serum creatinine (Scr).

2.9 Evaluation of intestinal mucosal barrier status

Collect colon tissue samples from patients before and after treatment. In addition, a control group was established from patients with no abnormalities detected during colonoscopy. All patients have signed informed consent forms.

RT-PCR was used to detect the RNA expression levels of tight junction (TJ) proteins (including JAM, claudin, occludin, ZO-1) before and after treatment to assess the repair of the intestinal mucosal barrier in UC patients. The primer sequences used for RT-PCR are listed in the table (Table 2).

GenesPrimer sequenceh-β-actinForward 5′-CTC​CAT​CCT​GGC​CTC​GCT​GTReverse 3′-GCT​GTC​ACC​TTC​ACC​GTT​CCh-ZO-1Forward 5′-GCA​TGA​TGA​TCG​TCT​GTC​CTA​CCT​GReverse 3′-CCG​CCT​TCT​GTG​TCT​GTG​TCT​TCh-JAM-AForward 5′-AGC​TGG​TCT​TTG​ATC​CCC​TGReverse 3′-CCA​TAC​CCA​TTC​CGT​GCC​TCh-Claudin-1Forward 5′-CTC​CTA​TGC​GGG​TGA​CAA​CAReverse 3′-GAG​ACC​ACC​ATT​AGG​GCT​CGh-OccludinForward 5′-AGC​AGC​GGT​GGT​AAC​TTT​GAReverse 3′-CCT​CCA​GCT​CAT​CAC​AGG​AC

Primer sequences of mRNA.

WB was also be used to detect TJ proteins in patients before and after treatment to evaluate the repair of the UC intestinal mucosal barrier. The antibodies and dilution ratios used were: JAM-A (Abcam, USA, 1:1000); claudin-1 (Abcam, USA, 1:5000); occludin (CST, USA, 1:1000); ZO-1 (Protein tech, China, 1:5000); GAPDH (Affinity, China, 1:5000).

2.10 Statistical analysis

Statistical analysis was performed using SPSS 19.0 software. In the descriptive analysis, quantitative data that follow a normal or approximately normal distribution were described using mean ± standard deviation (), while data that do not follow a normal or approximately normal distribution were described using the median (interquartile range), i.e., M (Q). Qualitative data were described using rates (%). For quantitative data that follow a normal or approximately normal distribution, a paired t-test was used, and for data that do not follow a normal or approximately normal distribution, the rank-sum test was used. Categorical data were analyzed using the chi-square test (2 test). All statistical tests were two-tailed, and a P-value of less than 0.05 was considered statistically significant.

Data were expressed as the arithmetic mean ± standard error of the mean (SEM). Data analysis was performed using GraphPad Prism 5.0 (GraphPad, USA). One-way analysis of variance (ANOVA) was used to assess statistically significant differences between groups, and Tukey’s test was used for multiple comparisons. A P-value of less than 0.05 indicated a statistically significant difference.

3 Results3.1 Qualitative analysis of CQE

CQE extracts were analyzed by UHPLC–Q Exactive Orbitrap–HRMS. The total ion chromatograms in both negative and positive ion models are displayed in Figures 1A,B. A total of over 1,200 compounds in CQE were identified, including flavonoids, phenylpropanoids, carbohydrates and glycosides, terpenes, organoheterocyclic compounds, Phenols, Alkaloids, Amino Acids, Peptides and derivatives, among others Figure 1C. The top compounds with relatively large peak area included Gallic acid, Matrine, Oxysophocarpine, Ellagic acid, Prim-O-glucosylcimifugin, Cytisinicline, Indigo, Indirubin, Tryptanthrin, and others Figure 1D.

Chemical identification of CQE using UHPLC–Q Exactive Orbitrap–HRMS. (A) The chemical total ion chromatogram (TIC) chromatogram of CQE in the positive ion mode. (B) The TIC chromatogram of CQE in the negative ion mode. (C) Structural classification of compounds contained in CQE. (D) Representative chemical components of CQE identified by UHPLC–Q Exactive Orbitrap–HRMS.

3.2 Baseline characteristics

The study enrolled 114 patients with UC, and the clinical baseline data are summarized in Table 3.

GroupNumberSex,n (%)Male73 (64.04)Female41 (35.96)Age 46.45 13.52Course of disease, M(Q)3.00 (6.75)Disease extension, n (%)E129 (25.44)E249 (42.98)E336 (31.58)Severity of Illness, n (%)Mild42 (36.84)Moderate55 (48.25)Severe17 (14.91)Disease type, n (%)Initial onset type13 (11.40)Chronic recurrent type101 (88.60)Past drug use, n (%)5-Asa79 (66.39)Steroids16 (13.45)Immunosuppressants4 (3.36)Biologics6 (5.04)Other14 (11.76)

Basic data of 114 patients with UC(,n = 114).

3.3 Case completion status

A total of 114 UC patients were enrolled in this study, among which 107 completed the clinical symptom assessment, 101 completed the laboratory index evaluation, and 101 completed the endoscopic and histopathological scoring (Figure 2).

CONSORT flowchart. Note: Missing data in laboratory and endoscopic evaluations were due to incomplete follow-up examinations.

3.4 Main results: improvement in inflammatory activity by day 143.4.1 Primary endpoint: change in modified Mayo score

The primary endpoint, defined as the change in modified Mayo score, showed a significant improvement after treatment. 101 UC patients underwent modified Mayo scoring before and after treatment. The post-treatment score (2.70 ± 2.30) significantly decreased from the pre-treatment score (7.48 ± 2.44) (t = 14.24, P < 0.01). According to the defined criteria, all 101 patients showed improvement in disease severity, with a clinical response rate of 94.06% (95/101) and a clinical remission rate of 66.34% (67/101).

3.4.2 Secondary endpoint: clinical symptom assessment (SCCAI)

By recording patients’ daily symptoms, significant relief was observed after 3 days of enema treatment, with a rapid drop in symptom scores by the 4th day (Figure 3). By Day 14, scores stabilized, reaching or approaching a minimum of 0. Compared with baseline scores for bowel frequency (1.25 ± 0.92), blood in stool (1.79 ± 1.02), urgency of defecation (0.98 ± 0.98), extracolonic features (0.44 ± 0.44), and general wellbeing (3.64 ± 3.07), post-treatment scores were significantly reduced to 0.20 ± 0.54, 0.21 ± 0.61, 0.08 ± 0.28, 0.07 ± 0.20, and 0.31 ± 1.16, respectively (P < 0.001).

Simple clinical colitis activity index of 107 patients with UC after treatment ().

3.4.3 Endoscopic and histopathological evaluation

101 UC patients underwent a follow-up colonoscopy 14 days after the enema (Figures 4, 5). Post-treatment, there was significant improvement in colonic mucosal inflammation. For patients with lesions localized to the rectum or rectosigmoid region, symptoms such as mucosal hyperemia and edema diminished, vascular patterns became clearer, and erosion, ulcers, and bleeding improved. In patients with left-sided or extensive colitis, distal rectal mucosa also showed improvement, with mild hyperemia or erosion persisting, but no ulcers or bleeding. The MES score post-treatment (1.06 ± 0.71) was significantly lower than pre-treatment (2.50 ± 0.56) (t = 16.06, P < 0.05). The distribution of MES score post-treatment showed that 2.97% (3/101) scored 3, 20.79% (21/101) scored 2, 56.44% (57/101) scored 1, and 19.80% (20/101) scored 0, resulting in a mucosal healing rate of 76.24% (77/101).

Endoscopic Findings of UC Patients Before and After 14 Days of Enema Treatment. (A,B) (Before enema): Rectal mucosa shows congestion, edema with erosion and ulcers, covered with white exudate, loss of vascular pattern, and spontaneous bleeding observed (see ↓). (C,D) (After enema): Rectal mucosa appears smooth, with a mostly restored vascular pattern (see ↓), and a few small patches of congestion (see ↓).

Pathological Findings of UC Patients Before and After 14 Days of Enema Treatment (HE, ×10). (A) (Before enema): Crypt abscesses and extensive inflammatory cell infiltration are observed (see “↓”). (B) (After enema): No crypt abscesses are observed, and inflammatory cell infiltration is significantly reduced compared to before (lesion areas marked with “↓”, remission areas marked with “↓”). Note: These histopathological changes are consistent with the Geboes scoring results.

Post-treatment, inflammation cell infiltration in the mucosal layer of the affected intestinal tissue was significantly reduced. Histopathological findings showed a Geboes score of 2.33 ± 1.36 post-treatment compared to 3.80 ± 1.50 pre-treatment (t = 7.27, P < 0.001). Based on defined criteria, the histological remission rate was 38.61% (39/101).

3.4.4 Stratified evaluation3.4.4.1 Disease severity stratification

Among 101 UC patients, based on the modified Mayo score, 24 patients were categorized as mild, 61 as moderate, and 16 as severe. It was found that in mild patients, the post-treatment modified Mayo score (1.29 ± 0.68) significantly decreased from the pre-treatment score (4.38 ± 0.81) (t = 3.53, P < 0.001); moderate patients had a post-treatment score of (2.54 ± 1.83) compared to (7.66 ± 1.25) pre-treatment (t = 6.67, P < 0.001); and severe patients had a post-treatment score of (5.44 ± 3.06) compared to (11.44 ± 0.50) pre-treatment (t = 8.57, P < 0.001). Based on this, clinical remission and efficacy were evaluated for changes in disease severity before and after treatment (Table 2).

Pre- and post-treatment MES scores were assessed, revealing that mild patients had a post-treatment MES score of (0.80 ± 0.67) compared to (2.04 ± 0.45) pre-treatment; moderate patients had (1.05 ± 0.66) post-treatment versus (2.56 ± 0.53) pre-treatment; and severe patients had (1.50 ± 0.71) post-treatment versus (3.00 ± 0.00) pre-treatment. This was used to evaluate the endoscopic mucosal healing status (Table 4).

Disease severityCases (n)Clinical responseClinical remissionEndoscopic mucosal healingMild