INTRODUCTION: Colorectal cancer is the second leading cause of cancer death in the United States. Recent studies have led the American Cancer Society to recommend colorectal cancer screening begin at age 45 rather than 50 in the average risk patient. Patients often present with symptoms associated with colorectal cancer long before their diagnosis. Reasons for delays in diagnoses appear to be multifactorial. We aimed to further characterize the timing of diagnosis of colorectal cancer and factor contributing to its delay in patients younger than age 45. METHODS: We conducted a single quaternary center retrospective study of patients diagnosed with colon or rectal cancer between October 2007 and October 2018. We stratified patients by those diagnosed under age 45 and compared them to a control group of patients diagnosed above age 50. Patients with hereditary colorectal cancer or a family history of colorectal cancer were excluded. Time between symptom presentation and diagnosis, reasons for delay of diagnosis, demographics, comorbidities and family history and were recorded. Statistical analysis with chi-square and Wilcoxon sign-ranked tests were conducted using SPSS. RESULTS: Between October 2007 and October 2018, 122 cases of colorectal cancer were diagnosed at our institution in patients under the age of 45. The median age at diagnosis was 42 compared to 65 in patients above 50. Patients under 45 had a greater delay in diagnosis after initial report of symptoms compared to patients over 50 (15.4 vs 6.1 months, P < 0.0001). The most frequent cause of delayed diagnosis in both groups was found to be hesitation in presenting to a physician. Both patients diagnosed under the age of 45 and above 50 were predominantly male (55.1% and 51.6%). Patients diagnosed under the age of 45 had a lower prevalence of smoking compared to those above 50 (32.8% vs 56.8%, P < 0.0001). CONCLUSION: Our study demonstrates an alarming difference in the latency between presentation and diagnosis of colorectal cancer in those under 45 and above 50. Significant differences between the delay in diagnosis in patients below the age of 45 and those above 50 suggest that current guidelines may not be adequate in screening for colorectal cancer. Further studies aimed at risk stratification this younger age group are necessary. Additional efforts aimed at creating awareness on the risk of colorectal cancer in this population are necessary for both patients and providers.Table 1.: Comparison in patients diagnosed with colorectal cancer above age 50 and those diagnosed below age 45