The investigators propose to study the safety of autologous mesenchymal stromal cell transfer using a biomatrix (the Gore Fistula Plug) in a Phase I study using a single dose of 20 million cells. 15 adult patients, ages 18 years and older with cryptoglandular fistulas will be enrolled. Subjects will undergo standard adjuvant therapy including drainage of infection and placement of a draining seton. Six weeks post placement of the draining seton, the seton will be replaced with the MSC loaded Gore Fistula Plug; fistula plug as per current clinical practice. The subjects will be subsequently followed for fistula response and closure for 24 months. This is an autologous product derived from the patient and used only for the same patient.

The investigators propose to study the safety of autologous mesenchymal stromal cell transfer using a biomatrix (the Gore® Bio-A® Fistula Plug) in a Phase I study using a single dose of 20 million cells. 15 adult patients (age > 18 years) with cryptoglandular fistulas will be enrolled. Subjects will undergo standard adjuvant therapy including drainage of infection and placement of a draining seton. Six weeks post placement of the draining seton, the seton will be replaced with the MSC loaded Gore® fistula plug as per current clinical practice. The subjects will be subsequently followed for fistula response and closure for 24 months. Study visits are Day 1, Week 2, Week 4, Week 8, Week 12, Week 24, Week 52, and Week 104. This is an autologous product derived from the patient and used only for the same patient.

Inclusion Criteria

1. Males and females 18-65 years of age.
2. Residents of the United States.
3. Single-tract, transsphincteric anal fistula of cryptoglandular origin. Primary fistulas (no previous surgical treatment) and those who have failed previous surgical repairs
4. Have no contraindications to MR evaluations: e.g. pacemaker or magnetically active metal fragments, claustrophobia
5. Ability to comply with protocol
6. Competent and able to provide written informed consent

Exclusion Criteria

1. Inability to give informed consent.
2. Clinically significant medical conditions within the six months before administration of MSCs: e.g. myocardial infarction, active angina, congestive heart failure or other conditions that would, in the opinion of the investigators, compromise the safety of the patient.
3. Specific exclusions; Evidence of hepatitis B, C, or HIV
4. History of cancer including melanoma (with the exception of localized skin cancers)
5. Investigational drug within thirty (30) days of baseline
6. A resident outside the United States
7. Pregnant or breast feeding.
8. History of clinically significant auto-immunity (e.g. Crohn's disease) or any previous example of fat-directed autoimmunity
9. Previous allergic reaction to a perianal fistula plug.
10. If liposuction is not technically feasible
11. Allergic to local anesthetics
12. Pregnant patients or trying to become pregnant.
13. Non-enterocutaneous tracts (i.e. recto-vaginal, entero-vesicular)
14. Multi-tract, suprasphincteric and extrasphincteric fistula tract extensions
15. Active local infection associated with the fistula