Tailored Nutrition vs. Exercise Prehabilitation Before Colorectal Cancer Surgery

This study will test whether tailored nutritional support before surgery, alone or combined with a structured exercise program, can help adult patients recover better after surgery for colorectal (bowel) cancer. Participants will be randomly assigned to one of three groups: usual care, tailored nutritional support alone, or nutritional support combined with a structured exercise program (multimodal prehabilitation). The main goal is to find out whether either approach improves physical function 30 days after surgery, measured by how far participants can walk in 6 minutes (the 6-minute walk test). The study will also look at nutritional intake, physical function, quality of life, complications, hospital readmissions, and length of hospital stay. A total of 140 adult patients scheduled for surgery for colorectal cancer at hospitals in Northern Norway will be enrolled.

Inclusion Criteria: Patients undergoing elective colorectal cancer surgery who give informed consent and meet all of the following will be eligible: * Planned elective surgery for colorectal cancer * Age \>=18 years * If neoadjuvant treatment has been given, treatment must be completed and the patient must be scheduled for surgery * Able to understand Norwegian sufficiently to receive study information, complete questionnaires, and follow written and oral instructions * Able and willing to provide written informed consent Exclusion Criteria: * Known metastatic disease * Previous participation in structured multimodal prehabilitation as part of the current cancer treatment pathway before inclusion, for example during neoadjuvant therapy * Previous major gastrointestinal surgery considered by the treating clinician to substantially affect the planned colorectal cancer surgery or postoperative recovery * Physical impairment that prevents the participant from walking for six minutes or rising independently from a chair * Planned multivisceral resection and/or complex reconstruction due to locally advanced cancer * Ongoing severe nutritional support, such as parenteral nutrition, that limits the feasibility of the allocated intervention * Cognitive impairment that prevents the participant from understanding the intervention, exercise programme, questionnaires, or written and oral instructions * Severe comorbidity or other medical condition that, in the judgement of the treating clinician, precludes participation in structured exercise * Severe renal failure, including patients requiring dialysis or with clinically significant electrolyte disturbances * Inability to use the telemedicine technology required for follow-up when telemedicine-based follow-up is planned * No permanent address or expected hospital/institutional stay for more than 50% of the time between diagnosis and planned surgery