Efficacy and Safety of Upatinib in the Treatment of Active Anal Fistulas in Crohn's Disease

Inclusion Criteria: * Age ≥18 years and ≤70 years; * Make a clear diagnosis of CD according to the "Consensus Opinions on the Diagnosis and Treatment of Inflammatory Bowel Disease (Beijing, 2018)"; * The disease severity of CD was moderate and severe according to Crohn's diseaseactivityindex (CDAI), that is, CDAI score \> 220. * Complicated with active anal fistula, that is, on the basis of perianal MRI confirmation of anal fistula, the patient has perianal pain, fluid seepage and other symptoms, and the transanal surgeon judges that the symptoms are related to anal fistula activity; * Patients with previous thrombosis, including deep vein thrombosis, pulmonary thromboembolism, atrial thrombosis, peripheral artery thrombosis and cerebral thrombosis confirmed by imaging; * Informed consent. The subjects gave barrier-free informed consent, voluntarily participated in the clinical study and signed the informed consent. Exclusion Criteria: * History of allergy to the active ingredient of upatinib; * Severe damage of liver and kidney function; Hemoglobin \< 8g/L; * History of malignant tumor; * Patients with previous thrombosis; * Neutrophil count \< 1×109/L; , or lymphocyte count \< 500×109/L; * Patients with intestinal complications (including intestinal stricture with proximal intestinal dilation or intestinal fistula). Diagnosis based on CTE/MRE. * Presence of enterostomy; * With active severe infection (such as sepsis) or opportunistic infection (such as active tuberculosis, shingles); * Pregnant or planning pregnancy. * Patients with vaginal fistula; * Patients with anorectal stenosis.