One of the newest and most innovative medicinal approaches is cell therapy. Several clinical trials and experimental investigations have looked into the feasibility of treating CD-related fistulas with stem cells. The current indication for ALOFISEL® (active ingredient: Darvadstrocel) is the treatment of difficult perianal Crohn's fistulas that have not responded well to at least one conventional therapy or biotherapy. This brand-new cell therapy medication is created using amplified allogeneic human adult mesenchymal stem cells from adipose tissue (ADSC). The supplier mandates that two patients be booked for a single dose of ALOFISEL® due to the medication's expensive price-roughly €54,000 for a single dose of 120 million-which cannot be stored once thawed. Only one of the two patients receives therapy; the other serves as the backup patient. By doing this, another back-up patient who might receive no care at all is avoided. An developing alternate approach to allogeneic ADSC injection for the treatment of complicated anal fistulas in CD is autologous fat injection. In recent years, autologous fat grafts have been the subject of in-depth research. They are popular because it is simple to get clinical samples (lipoaspirate, adipose tissue), and because there are a lot of ADSCs in adipose tissue. Additionally, ADSCs show strong immunomodulatory and regenerative capacities. We would wish to compare the effectiveness of these two injection kinds on perianal fistulas as part of our care of CD.