Here investigators will carry out this phase II clinical trial to explore a effective therapeutic regimen of MSC in the Crohn's perianal fistula.

Peri-anal fistula is common seen in Crohn's disease. Treatments including surgery, antibiotics, immunosuppressive drug and infliximab improve the quality of life of the patients suffering Crohn's perianal fistula, but the recurrent rate is still high. MSC showed promising effect in the therapy of CD, but the standard treatment strategy is unclear. Here investigators will carry out this phase II clinical trial to explore a effective therapeutic regimen of MSC in the Crohn's perianal fistula.

Inclusion Criteria:

1. Age 18-65 years old, male or female;
2. refractory CD fistula, there are 1-2 and 1-3 in the mouth fistula;
3. Diagnostic CD at least three months;
4. CDAI <250;
5. were receiving drug treatment (5-ASA and hormones> 4 weeks, immunosuppressants and biological agents> 8 weeks);
6. signed informed consent.

Exclusion Criteria:

1. with intestinal obstruction, stenosis, or perianal abscess;
2. pregnant or lactating women;
3. infection needs antibiotics persons;
4. rectovaginal fistula;
5. complex anal fistula more than two inside the mouth;
6. stenosis or perforation CD;
7. perianal infection;
8. could not do rectal or anal stenosis local injection therapy;
9. with acute enteritis;
10. , liver and kidney dysfunction;
11. a month have used other drugs are in clinical trials;
12. no conditions or unwilling to carry out MRI inspected;
13. who are adjusting therapy;
14. HIV patients;
15. The combined active hepatitis or tuberculosis; Occurred in 16) 6 months opportunistic infections, or severe infections occur within three months;

17) In the past five years, those who suffer from cancer; 18) there is a history of lymphoproliferative disease.