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 (age 18 and greater) with persistent symptomatic post-surgical gastrointestinal leaks despite current standard radiologic and endoscopic therapies will be enrolled. The subjects will be subsequently followed for fistula response and closure for 18 months. This is an autologous product derived from the patient and used only for the same patient.

Visit 1: Patients will be evaluated for eligibility (inclusion/exclusion checklist) and written, informed consent will be obtained. Patients will undergo general exam with vital signs. Patients will be scheduled for a fat biopsy to collect the tissue needed to grow MSC. In the event there is no cell growth from the tissue obtained from the first biopsy, one further attempt will made from a second tissue sample from this patient. However, if the second attempt fails to grow cells, no further attempts will be made, and the subject will not continue in the study.

Visit 2 (Week 0; Day 0): Patients will undergo an interventional endoscopy, the fistula tract will be assessed and the stem cell coated will be placed endoscopically.

Study visit will be as follows:

Visit 3 (Week 0; Day 1) Visit 4 (Week 2; Month 1) Visit 5 (Week 4; Month 1) Visit 6 (Week 8; Month 2) Visit 7 (Week 12; Month 3) Visit 8 (Week 24; Month 6) Visit 9 (week 52; Month 12) Visit 10 (Week 78; Month 18)

Inclusion Criteria

1. Males and females 18-75 years of age.
2. Residents of the United States.
3. Patients with persistent symptomatic fistulas arising after gastro-esophageal resections, enteric or colonic resections or Bariatric surgeries.
4. Single-tract fistula
5. Have no contraindications to imaging evaluations: e.g. contrast allergies
6. Ability to comply with protocol
7. Competent and able to provide written informed consent
8. Must have failed standard conservative therapy which includes at least one endoscopic attempt to resolve fistula. Standard conservative management includes drainage of sepsis, antibiotics, nutritional support, etc. Endoscopic closure attempt with devices such as, but not limited to; endo-stitch, clipping, surgical sealants, etc. This attempt may be with or without diversion of the luminal contents by stenting.
9. Radiographic Imaging within 7 days of fistula plug placement (e.g. CT, PET, etc.).

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;

   a. Evidence of hepatitis B, C, or HIV

4. Investigational drug within thirty (30) days of baseline

5. A resident outside the United States

6. History of clinically significant auto-immunity (i.e. Inflammatory Bowel Disease).

7. Previous allergic reaction to a fistula plug.

8. If obtaining sufficient adipose tissue for manufacturing is not technically feasible

9. Allergic to local anesthetics

10. Pregnant patients or trying to become pregnant or breast feeding.

11. Non-enterocutaneous tracts

12. Fistula output >2000 ml/day

13. Multiple or end fistulas

14. Fistulous tract <2 cm in length

15. Fistulous tract or defect >1 cm in diameter,

16. Fistulas opening into abdominal wall defect.

17. Diseased adjacent bowel, fistula in the radiation field, persistent distal obstruction or malignancy

18. Patients on immunosuppression or chemotherapy

19. Uncontrolled diabetes, i.e. blood sugar more than 200

20. Sepsis

21. Fistulas arising from a malignant lesion

22. Patients with obstructive malignancies

23. Patients with stage III and/or stage IV cancers. The investigators will exclude patients with stage III or IV cancers, poorly differentiated cancers and patients with less than accepted disease free surgical margins.