The purpose of this study is to determine the best method for cleaning wounds during surgery for patients with Stage 3 pilonidal disease. The investigators will compare the standard wound cleaning solution, saline, with a different solution called hypochlorous acid (Vashe, Urgo Medical) to see which one helps wounds heal faster after surgery.

This study will evaluate whether irrigating the surgical wound with hypochlorous acid solution (Vashe, Urgo Medical) during excision of Stage 3 pilonidal disease leads to faster wound closure compared with normal saline irrigation. The goal is to identify which intraoperative irrigation solution produces better healing outcomes and could be adopted as the preferred standard approach for future patients.

Patients who present to the Pediatric General Surgery Clinic at Stanford with pilonidal disease complaints will be screened for potential enrollment by the principal investigator and clinic provider. During the clinic visit, the study will be explained to the patient and their guardian(s). A retrospective review of the medical record to collect demographic information, prior treatment history, and disease severity will be conducted to confirm eligibility.

On the day of surgery, participants will be prospectively randomized using a pre-specified allocation sequence to one of two intraoperative wound irrigation groups: normal saline or Vashe (hypochlorous acid). During the operation, the surgeon will irrigate the post-excision wound with the solution assigned by randomization. All other aspects of the surgical procedure will follow standard clinical protocols.

After surgery, participants will be monitored for wound healing using photographs of the surgical site. Photographs will be requested on postoperative days 0, 2, 5, 7, 10, and 14 (± 1 day), and then weekly until the wound is closed. Study personnel will review submitted images to track wound healing over time, document any complications, and determine the time to wound closure. Recurrence of pilonidal disease at the original surgical site will be assessed by clinical examination in the clinic at 3-month intervals for 2 years after surgery.

Inclusion Criteria:

• Stage 3 pilonidal disease according to the Stanford Pilonidal Severity Staging System

Exclusion Criteria:

• Patients with pilonidal disease that is not classified as stage 3
• Intellectual disability precluding the patient and/or guardian from being able to consent