Inclusion Criteria:  Voluntary written informed consent of the participant or their legally authorized representative has been obtained prior to any screening procedures. Patients with a diagnosis of Crohn's disease based on radiology, endoscopy and/or histology Males and females 18-80 years old.  Patients undergoing an ileocolonic resection with ileocolonic anastomosis (with or without temporary ileostomy) within 3 and 40 days prior to the Screening visit.  Patients who underwent an ileocolonic resection with ileocolonic anastomosis with a temporary ileostomy are also eligible if the ileocolonic resection was performed within eight months prior to the Screening visit, and the restoration of the faecal stream was performed within 3 and 40 days prior to the Screening visit.  Patients having an increased risk for postoperative recurrence for any of the following reasons:  Penetrating disease as reason for ileocolonic resection Previous ileocolonic resection within ten years of index surgery Two or more previous ileocolonic resections Active smoking Biological therapy for Crohn's disease within 3 months of index ileocolonic resection Curative ileocolonic resection. All inflamed colon segments should have been removed. Strictureplasties in the small bowel not involving the anastomotic region are allowed. Patients previously failing at least three months of steroids and/or three months of immunosuppressive therapy, or showing intolerance or a real contraindication for any of these therapies. Patients able and willing to start and continue biological therapy, and this at the timepoint indicated through study randomization  Exclusion Criteria:  Participant has a history of primary non response or secondary loss of response to all five biological therapies of interest, namely adalimumab, infliximab, ustekinumab, vedolizumab and risankizumab.. Any disorder, which in the Investigator's opinion might jeopardise the participant's safety or compliance with the protocol. Any prior or concomitant treatment(s) that might jeopardise the participant's safety or that would compromise the integrity of the Trial. Participation in an interventional Trial with an Investigational Medicinal Product (IMP) or device. Patients initiating biological therapy for CD as part of another clinical trial or a medical need program. Patients not understanding Dutch, French, German or English. Patients with ulcerative colitis or inflammatory bowel disease type unclassified. Patients with an ileorectal anastomosis, or an ileal pouch-anal anastomosis. Patients with active perianal disease. Patients with a colorectal stenosis. Patients with an ostomy. Patients with sepsis or other postoperative complications necessitating the use of antibiotics for more than ten days after ileocolonic resection or restoration of the faecal stream. Patients with (an imminent risk) of a short bowel syndrome. Patients who had qualifying ileocolonic resection for dysplasia or cancer without ongoing inflammation. Patients with liver test abnormalities (aspartate transaminase, alanine transaminase, alkaline phosphatases, or bilirubin > 2 upper limit of normal), leukopenia (<3000 white blood cells 109/L, <1500 neutrophils 109/L ), thrombocytopenia (platelets < 50.000/mm3). Patients with severe renal, pulmonary or cardiac disease. Ongoing alcohol or substance abuse.