The eligible population consisted of individuals with anal fissure awaiting surgical intervention. Individuals aged 18 years or older were included, diagnosed with anal fissure and who voluntarily agreed to participate in the research. Those who had some pelvic inflammation and who had already undergone a surgical procedure and had recurrence were excluded from the studyThe selected individuals underwent a standardized anamnesis of the service, answered questionnaires on symptoms of intestinal constipation (Rome IV Criteria and the Bristol Scale), underwent a physical evaluation by a trained professional, and then began the application of the research protocol. The Antares brand Laser device was used for 3 sessions with an interval of 24 hours. The Visual Analogue Scale (VAS) was used before starting treatment, after the first and second sessions, and 1 week after the third session. In addition, at the end of the treatment, the closure, or not, of the lesion was verified, and the questionnaires performed prior to phototherapy were reapplied. The VAS assesses the patient's level of pain, which can be divided into mild pain (1-2), moderate pain (3-7), and severe pain (8-10). The Bristol Scale is based on the identification of the patient's consistency of stools, while types 1-2 correspond to constipation, 3-4 indicate normal intestinal rhythm, 5 indicate lack of fiber, and 6-7 correspond to diarrhea.

Inclusion Criteria:

• individuals with the diagnosis of anal fissure that accepted to participate as volunteers in the clinical trial

Exclusion Criteria:

• individuals with pelvic inflammation
• individuals who have been through surgical procedures
• individuals who have relapse