Over the last decades, the 3-year recurrence rates for patients with stage I and II colorectal cancer have decreased to just 5% and 12%. The follow-up program offered to stage I and low-risk stage II patients has not changed accordingly and is still focused solely on recurrence detection. Moreover, it is a one-size-fits-all program, i.e. most of the follow-up resources are spent on non-recurrence patients who do not benefit. Up to 50% of cancer survivors suffer from reduced quality of life related to fear of cancer recurrence, treatment-related psychological distress, and/or severe late adverse effects of a biopsychosocial and/or organ-specific origin. Today many of these symptoms can be treated effectively. However, no systematic program aimed at monitoring and addressing the symptoms has been implemented yet. The current project is testing a newly developed, digitally managed, patient-centered follow-up program that focuses on individual patient needs, including fear of cancer recurrence, psychological well-being, management of late adverse effects, and recurrence surveillance. This new program will be compared to the current standard of care in a national network of 11 colorectal cancer surgical centers in four of five Danish regions. Patients in the intervention group will receive the following: 1. Risk-stratified circulating tumor DNA (ctDNA) guided recurrence surveillance. 2. Late adverse effects monitoring with electronic patient-reported outcome measures, which are validated questionnaires that can identify and qualify late adverse effects. 3. Systematic treatment for organ-specific and/or biopsychosocial late adverse effects. 4. A digital care guide, to support the patient trajectory through the follow-up program, as a smartphone app. Patients in the standard group will receive standard-of-care follow-up. The primary study endpoint will be the difference in health-related quality of life between the intervention and standard group. Secondary outcomes include e.g., comparison of health-related costs, differences in fear of cancer recurrence, recurrence-free survival, and patient satisfaction. The investigators expect the new follow-up program to be better than the standard-of-care program in terms of the primary endpoint - quality of life - without compromising recurrence detection, and without increasing costs.