Study halted due to lower success rates than expected, under evaluation, will potentially resume at a later date.

The purpose of this study is to determine whether treatment with laser coagulation is an effective and safe treatment option for patients with anal fistula

Treatment of anal fistula remains a challenge - the only truly effective treatment available (fistulotomy) involves very high rates of anal incontinence if performed on the majority of patients, and a vast number of alternative, sphincter-preserving treatments have been developed and evaluated in the past decades. The treatment of anal fistula with laser coagulation causes the fistula to collapse and subsequently heal, without having to add any external materials. The available published studies show that the treatment is safe regarding infection and incontinence, and that a majority of the patients treated show complete healing. There is however a need for more prospective studies to ascertain these preliminary facts.

Inclusion Criteria:

1. Subject has been informed of the nature of the study, agrees to its provisions, and has provided written informed consent.
2. Subject must be at least 18 years of age
3. Subject must have a verified anal fistula (by transanal ultrasound performed by treating surgeon)
4. Subject must have a clean and infection-free fistula tract (no cavities seen on transanal ultrasound)
5. Subject must be able to comply with study and study follow-up requirements.

Exclusion Criteria:

1. Subject with anorectal fistula due to Crohn's disease
2. Subject has an undrained abscess in fistula tract (cavities as seen on transanal ultrasound)
3. Subject has fistula with side tracts (as seen on transanal ultrasound)
4. Subject is unable or unwilling to provide informed consent.