Mesenchymal Stem Cells (MSCs) for Perianal Fistula

Inclusion Criteria: * Men and Women 18-75 years of age with a diagnosis of unhealing perianal fistulas in the setting of Crohn's disease and must be on maximal standard of care therapy (e.g., antibiotics, 5-ASA, and immunomodulator, anti-TNF, anti-integrin, and anti-interleukin therapies) for at least six months duration. * Presence of perianal fistula with maximum of two internal fistula tracts and a maximum of three external openings based on clinical assessment and MRI. Fistula must have been draining for at least 6 weeks prior to the screening visit. * Medically refractory perianal fistulizing Crohn's disease (i.e., standard of care such as antibiotics, immunosuppressives) * Have no contraindications to MR evaluations: e.g., pacemaker or magnetically active metal fragments, claustrophobia * Ability to comply with protocol * Competent and able to provide written informed consent * Concurrent Crohn's-related therapies with stable doses corticosteroids, 5- ASA drugs, immunomodulators, anti-TNF therapy, anti-integrin and anti-interleukin therapies are permitted. * A female participant and of childbearing potential must have a negative serum or urine pregnancy test at time of screening, and must not plan to become pregnant during the study. Exclusion Criteria: * Inability to give informed consent. * Clinically significant medical conditions within the six months before administration of MSCs: e.g. myocardial infarction, active angina, congestive heart failure or other condi…