Chinese Herbal Retention Enema for the Treatment of Ulcerative Colitis

This article demonstrates a Chinese herbal retention enema method for treating ulcerative colitis, which can effectively improve patients' clinical symptoms and quality of life.

Ulcerative colitis (UC) is a globally prevalent and refractory disease that imposes a substantial socioeconomic burden, with no universally effective treatment currently available. Traditional Chinese medicine (TCM) demonstrated promising therapeutic potential in UC management, particularly through the application of Chinese herbal retention enema, which is gaining increasing international recognition. This method involves the rectal administration of an herbal decoction, which is retained for a designated period to ensure optimal contact with and absorption by the colonic mucosa. Compared to oral administration, this method offers distinct pharmacological advantages by bypassing hepatic first-pass metabolism, enhancing therapeutic effects, and minimizing systemic side effects. This study presents a comprehensive protocol for Chinese herbal retention enema in UC treatment, including patient assessment, material preparation, position selection, enema administration, postoperative care, and emergency management. A clinical trial was conducted with 22 UC patients divided into control and enema groups. Therapeutic outcomes were evaluated using individual symptom scores and the Inflammatory Bowel Disease Questionnaire (IBD-Q). The results indicated that Chinese herbal retention enema had a more significant advantage in improving clinical symptoms (mucopurulent bloody stools and abdominal pain) and quality of life (intestinal symptoms, systemic symptoms, and social functioning) compared to the control group (p < 0.05). These findings suggest that Chinese herbal retention enema represents an effective, well-tolerated, and patient-adaptable therapeutic approach, offering a promising complementary treatment option for UC management.

Ulcerative colitis (UC) is a chronic, nonspecific inflammatory bowel disease primarily affecting the colon and rectum, characterized by persistent or recurrent diarrhea, mucopurulent bloody stools, abdominal pain, tenesmus, and varying degrees of extraintestinal symptoms¹. As a growing global health concern, UC exhibits a steadily increasing annual incidence, afflicting approximately 5 million patients worldwide in 2023, thereby imposing substantial burdens on healthcare systems and societies^2,3. Despite advances in pharmacological interventions, current therapeutic strategies remain nonspecific and suboptimal. Mainstay treatments, including 5-aminosalicylic acid derivatives, glucocorticoids, immunomodulators, and biologics, are frequently associated with severe adverse effects. For example, mesalazine often causes pancreatitis, cardiotoxicity, and hepatotoxicity⁴, while corticosteroids commonly lead to weight gain, osteoporosis, and gastrointestinal bleeding⁵. Moreover, these medications tend to induce drug resistance and demonstrate limited efficacy in preventing disease recurrence⁶. Moreover, the high cost of some drugs places considerable economic strain on patients' families⁷. Thus, there is an urgent need to develop safer and more cost-effective therapeutic alternatives.

Traditional Chinese Medicine (TCM) possesses a unique theoretical system, with medicinal substances primarily derived from natural sources such as plants, animals, and minerals, offering potential multi-target therapeutic effects, relatively favorable safety profiles, and economic accessibility⁸. With a documented history spanning thousands of years in the management of UC, TCM has garnered increasing validation for its ability to alleviate symptoms, reduce recurrence, and minimize adverse reactions^9,10,11. Given the specific anatomical location of UC, local administration through the colorectal route is often more beneficial than oral administration^12,13. Historical records indicate that as early as 200 AD, Chinese herbal retention enemas were employed in clinical practice¹⁴. This method involves the rectal administration of herbal decoction, which is retained for a designated period to ensure optimal contact with and absorption by the colonic mucosa¹⁵. In recent years, the Chinese herbal retention enema technique has gained international recognition and has been applied to various conditions, including acute pancreatitis¹⁶, chronic kidney disease¹⁷, and gynecological disorders¹⁸. Its application is particularly notable in colonic diseases^19,20. Compared with oral drug administration, Chinese herbal retention enema delivers active compounds directly to the site of pathology, bypassing first-pass hepatic metabolism and minimizing degradation by digestive enzymes. This enhances the bioavailability of active components while reducing gastrointestinal irritation and systemic toxicity²¹. Notably, the rich vascularization and thin-walled venous structure of the rectal mucosa facilitate rapid drug absorption, promoting the resolution of inflammation and the repair of tight junctions within the intestinal mucosa, thereby improving overall mucosal integrity²². Although Western medicine has also adopted local administration methods, such as rectal delivery of 5-aminosalicylic acid and corticosteroids, to minimize systemic side effects, comparative evidence indicates that Chinese herbal retention enemas demonstrate superior therapeutic efficacy alongside a more favorable safety profile²¹.

Despite these advantages, the clinical application of Chinese herbal retention enemas remains limited due to the absence of standardized protocols and insufficient familiarity among healthcare professionals. Therefore, this paper systematically presents a standardized protocol for administering Chinese herbal retention enemas in the treatment of UC. The overall aim is to provide a detailed description of the procedure, including key steps and precautions, to ensure its clinical feasibility, reproducibility, and broad applicability in clinical practice.

The protocol has been approved by the Ethics Committee of the Hospital of Chengdu University of Traditional Chinese Medicine (Ethics No.: 2024KL-182-01). The operational procedures comply with the clinical guidelines of the Hospital of Chengdu University of Traditional Chinese Medicine. Informed consent was obtained from all patients for participation in the study.

1. Patient assessment

1. Confirm that the diagnosis meets the criteria for UC²³. Verify the patient is willing to accept Chinese herbal retention enema treatment and has signed an informed consent form.
2. Exclude patients with serious complications, such as lower gastrointestinal bleeding, obstruction, perforation, severe heart failure, liver or kidney dysfunction, hematological disorders, malignant tumors, mental disorders, or a history of allergy to Chinese herbs. Also, exclude patients with perianal skin lesions, severe hemorrhoids, or those who have undergone anal, rectal, or colonic surgery within the past 3 months. Exclude pregnant or lactating females.

2. Patient preparation

1. Instruct the patient to empty their bowels and bladder 30 min before the enema procedure. Explain the procedure steps, safety precautions, and therapeutic benefits in detail to alleviate anxiety and ensure patient cooperation.
2. Perform a routine cleansing enema prior to the herbal retention enema if fecal residue is present. Prepare a warm saline solution (approximately 500-1000 mL) at body temperature (37 °C-40 °C). Close the enema bag tube clamp to prevent leakage and fill the enema bag with warm saline.
3. Position the patient in left lateral decubitus with knees flexed. Loosen the clothing and pull the pants down to mid-thigh, fully exposing the anal area. Lubricate the rectal tube with paraffin oil and gently insert it into the anus to a depth of 7-10 cm, guided by the graduated centimeter markings on the proximal segment of the tube.
4. Hang the enema bag on the infusion stand, ensuring that the liquid level is approximately 40 cm above the anus. Open the clamp of the rectal tube and allow the warm saline solution to flow slowly into the rectum. Once the infusion is complete, close the clamp, carefully remove the rectal tube, and clean the anus with wet tissue. Instruct the patient to lie flat and retain the saline for 5-10 minutes to facilitate adequate bowel distension and cleansing.
5. After the retention period, provide the patient with a bedpan to evacuate the saline and fecal. Assess the clarity of the expelled solution to determine whether further enemas are required. Repeat the enema procedure 2-3 times, if necessary, until the discharged saline is clear and free of fecal residue. If the patient develops pallor, cold sweat, severe abdominal pain, or panic, stop immediately and notify the physician.

3. Material preparation

1. Preparation of herbal decoction
   1. Weigh the following herbs (Figure 1): Sanguisorba officinalis L. (Sanguisorbae radix) 20 g, Sophora japonica L. (Sophorae flos) 10 g, Portulaca oleracea L. (Portulacae herba) 10 g, Baphicacanthus cusia (Nees) Bremek. (Indigo naturalis) 30 g, Paeonia lactiflora Pall. (Radix paeoniae rubra) 10 g.
   2. Place the herbs in a clay pot. Add enough cold water to submerge up to 2-3 cm. Soak the herbs for 30 min.
   3. Bring the water to a boil, then simmer for 30 min. Filter through two layers of medical gauze and retain the decoction.
   4. Add cold water again to submerge the herbs by 2-3 cm. Bring it to a boil once more and simmer for another 30 min. Filter through two layers of medical gauze and retain the decoction.
   5. Combine the two decoctions and allow it to cool to a suitable temperature (approximately 39 °C-41 °C) for use.
2. Preparation of other materials
   1. Prepare an asepsis enemator for a single-use kit (including a single-use sterile enema device, disposable gloves, a disposable treatment tray, a medical treatment towel, and paraffin oil), a water thermometer, gauze, a cushion, a bedpan, and a privacy screen (Figure 2 and Table of Materials).

4. Treatment procedure

1. Administer conventional treatment to the control group: prescribe oral mesalazine enteric-coated tablets (4 g/day), combined with a personalized herbal decoction. Provide the enema group with additional daily Chinese herbal retention enemas.
2. Confirm the patient's information (name, age, hospitalization number). Ensure the patient has emptied their bladder and bowel. Confirm that the patient has signed the informed consent form. Re-evaluate the patient's condition and assess the patient for any discomfort or adverse symptoms that may contraindicate the procedure. Check the expiration dates and integrity of all equipment.
3. Close the doors and windows and adjust the room temperature to a comfortable level (approximately 22 °C-28 °C). Use a privacy screen to protect the patient's privacy.
4. Wash hands, don gloves and a mask. Inspect the perianal area for lesions or contraindications.
   1. Assess the skin condition: Inspect for redness, swelling, irritation, warmth, tenderness, or discharge.
   2. Examine for hemorrhoids: Palpate and visually inspect swelling, prolapse, or bleeding.
   3. Check for fissures or ulcers: Inspect for cracks, tears, or open sores around the anus.
   4. Examine for abscesses or infections: Palpate for lumps, swelling, redness, pus, or fluctuance.
   5. Ensure perianal hygiene: Clean the area thoroughly to remove fecal residue or debris.
   6. Identify contraindications: Report any concerning findings (e.g., recent surgery or infections) to the physician immediately.
5. Position the patient in left lateral decubitus with knees flexed. Loosen the clothing and pull the pants down to mid-thigh, fully exposing the anal area. Place a medical drape under the buttocks and elevate the hips by 10 cm using a cushion (see Figure 3).
   1. Adjust the patient's position based on the lesion location: for rectal and sigmoid colon lesions, use the left lateral position; for ileocecal lesions, use the right lateral position.
6. Measure the herbal decoction temperature (39 °C-41 °C) using a water thermometer. Close the enema bag tube clamp to prevent leakage. Fill the disposable enema bag with ≤ 200 mL of the decoction and hang it, ensuring the liquid level is no more than 30 cm from the anus.
7. Lubricate the rectal tube tip with paraffin oil. Instruct the patient to perform deep oral breathing. Gently insert the tube 15-25 cm into the rectum.
   1. Adjust the insertion depth based on the lesion location: for lesions in the rectum and sigmoid colon, insert the tube 15 to 20 cm; for lesions in the sigmoid or descending colon, insert 18 to 25 cm.
8. Open the enema bag tube clamp and slowly drip the herbal decoction, adjusting the infusion rate based on the patient's condition and tolerance. Maintain a total infusion time of 15-20 min. Continuously observe the patient and inquire about their tolerance. Adjust the infusion rate or discontinue the procedure if discomfort or the urge to defecate arises.
   1. Stop the enema immediately if the patient shows signs of rapid pulse, pale complexion, cold sweats, severe abdominal pain, or palpitations. Notify the physician immediately.
9. Clamp the tube upon completion. Remove the tube slowly while asking the patient to contract anal sphincters. Cleanse the perianal area with gauze.
10. Instruct the patient to remain in the supine position with hips elevated for 60 min. Provide a bedpan for controlled evacuation after the retention period.
    1. For patients with poor retention (< 30 min), add 2-3 mL of 1% lidocaine to the herbal decoction after physician approval.
11. Dispose of biohazardous waste in designated containers. Disinfect reusable equipment according to the Technical Specification for Disinfection in Healthcare Facilities²⁴. Document the procedure details and the patient's response.

5. Postoperative care

1. Open the windows to ensure proper ventilation. Replace the bed linens with clean sheets.
2. Check for signs of abdominal distension, diarrhea, constipation, or other symptoms. Instruct the patient to avoid straining during bowel movements. Guide the patient to monitor and record daily stool characteristics, including frequency, color, odor, and consistency. Collect stool samples for further examination if abnormalities are observed.
3. Advise the patient to rest and follow a light, easily digestible diet. Prohibit the consumption of hard, cold, raw, high-fiber, spicy, fried foods, and dairy products.
4. Monitor the patient's vital signs (temperature, blood pressure, pulse, heart rate, and respiration rate) at 15 min intervals for the first hour after the procedure. Thereafter, assess the vital signs hourly for the next 4 h. Document any changes in symptoms promptly.

6. Drug efficacy evaluation

1. Primary efficacy indicators
   1. Assess UC symptoms using the individual symptom scores recommended by the Experts' consensus on traditional Chinese medicine diagnosis and treatment of ulcerative colitis (2023)²⁵ Score the following symptoms:
      Diarrhea: 0 (none), 3 (<4 times/day), 6 (4-6 times/day), 9 (>6 times/day)
      Mucopurulent Bloody Stools: 0 (none), 3 (small amounts of pus/blood), 6 (predominant pus/blood), 9 (entire stool composed of pus/fresh blood)
      Abdominal Pain: 0 (none), 3 (mild/intermittent), 6 (moderate/recurrent), 9 (severe/cramping)
      ​Tenesmus: 0 (absent), 1 (present)
   2. Perform a baseline assessment upon admission. Administer the Chinese herbal retention enema daily for 14 consecutive days. Conduct the final efficacy evaluation 24 hours after the last enema. Compare post-treatment scores with baseline scores.
2. Secondary efficacy indicators
   1. Assess quality of life using the Inflammatory Bowel Disease Questionnaire (IBD-Q)²⁶. Evaluate the patient's social function, emotional status, systemic symptoms, and bowel-related symptoms. Higher scores indicate improved quality of life.
   2. Perform a baseline assessment upon admission and a follow-up evaluation 14 days after treatment completion.

This study included 22 UC patients from the Department of Gastroenterology at the Hospital of Chengdu University of Traditional Chinese Medicine. The control group received conventional treatment (oral mesalazine enteric-coated tablets combined with a personalized herbal decoction), while the enema group received additional daily Chinese herbal retention enemas.

The outcome measures of this study were the individual symptom scores and the IBD-Q scores. The individual symptom scores are shown i...

UC is a chronic inflammatory disease primarily affecting the colorectal mucosa. Research has shown that rectal formulations of 5-aminosalicylic acid and corticosteroids can directly target the lesions, effectively reducing systemic reactions and demonstrating higher efficacy and safety compared to oral treatments^12,27. However, these medications are still associated with unavoidable side effects, which has prompted increasing attention to the application of TCM a...

The authors have nothing to disclose.

This work was supported by the Sichuan Provincial Administration of Traditional Chinese Medicine Scientific and Technological Research Special Project (2024zd004) and the Sichuan Provincial Key Research and Development Project (2024YFFK0171).