The Effect of Methylene Blue Infiltrating Injection on Anal Pain After Milligan-Morgan Surgery: a Randomized Controlled Clinical Study

The Ethics Committee of the Second Hospital of Chinese Medicine

Status

Enrolling by invitation

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT06660680

Acronym

MBI

Enrollment

Registered

2024-10-28

Start date

2024-10-25

Completion date

2025-10-01

Last updated

2024-10-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Mixed Hemorrhoids

Keywords

Milligan-Morgan surgery

Brief summary

A variety of analgesic strategies are available following mixed hemorrhoids surgery, including pharmacological interventions (7), acupuncture, moxibustion, and electroacupuncture . Medications such as opioid analgesics and non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used but can be associated with side effects including nausea, vomiting, and gastrointestinal bleeding, with long-term use potentially leading to addiction (8). Complementary therapies require skilled administration and regular treatment sessions. Methylene blue (MB), a cationic thiazine dye extensively utilized as a biological stain and chemical indicator, has been increasingly recognized for its potential analgesic properties (9). In the present study, methylene blue infiltrating injection (MBI) was administered to treat anal pain resulting from Milligan-Morgan surgery, with the aim of assessing its analgesic efficacy and safety profile.

Interventions

DRUGMethylene Blue

Received MBI treatment to their surgical incisions upon completion of surgery

Study design

Allocation

RANDOMIZED

Intervention model

PARALLEL

Primary purpose

TREATMENT

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to 75 Years

Healthy volunteers

Inclusion criteria

①Alignment with the diagnostic criteria for mixed hemorrhoids as outlined in the American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Management of Hemorrhoids ; ②Provision of informed consent following a thorough comprehension of the study's aims; ③An age bracket of 18 to 75 years; ④Satisfaction of surgical indications. \-

Exclusion criteria

①Presence of anal fistula, anal fissure, perianal abscess, enteritis, or other intestinal pathologies; ②Patients with known allergies; ③Impaired liver or kidney function; ④Pregnancy or lactation. \-

Design outcomes

Primary

Measure	Time frame	Description
Pain	pain scores at 6, 24, 48, and 72 hours postoperatively	Visual Analog Scale (VAS) scores

Countries

China

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026