Cologuard® is a noninvasive, at-home screening test which is prescribed to detect colorectal cancer and advanced precancerous lesions in patients who are aged 45 and older and are at risk [1]. The test functions by identifying abnormal DNA markers found to be associated with colorectal neoplasia as well as the presence of occult hemoglobin in the stool, which both serve as potential indicators of cancerous or precancerous lesions in the colon [2]. It is a test that has risen in popularity. The use of DNA stool tests for colorectal cancer screening has increased more than nine-fold since 2018, rising from 3% of screenings in the first quarter of 2018 to 31% of screenings in the fourth quarter of 2023 [3].

The Cologuard® has exhibited a high sensitivity for detecting CRC in clinical studies making it an important tool for screening and early detection. The Cologuard® test has two generations having undergone improvement in sensitivity and specificity. The first generation demonstrated a sensitivity of 92% for colorectal cancer and 42% for precancerous lesions [1]. One study showed that the Cologuard® detected significantly more cancers than other stool-based tests but also gave more false positive tests [1]. In comparison FIT test had a sensitivity of 73.8% for colorectal cancer and 23.8% for pre-cancerous lesions. This shows that Cologuard has increased sensitivity but decreased specificity yielding more false positives requiring colonoscopy. Apart from that FIT is recommended yearly while the Cologuard test is recommended after 3 years. Studies have shown that adherence to yearly testing remains poor with one study having repeat testing of 23.4% in year 2 and 10.6% in year 3 [4].

However, as a stool-based test it presents with limitations as it does not provide direct visualization of the colon and cannot be used to identify or remove polyps and unable to identify other colorectal diseases [5]. Despite this drawback, the Cologuard® is widely used as a convenient and effective screening option, particularly for individuals who may be reluctant to undergo a colonoscopy [3]. While the Cologuard® is highly sensitive in detecting colorectal cancer or precancerous lesions, it remains a screening tool rather than a diagnostic test [3]. Suboptimal rates of follow-up represent a missed opportunity in early detection and prevention.

Timely follow-up is essential, as delays in colonoscopy following a positive stool-based test have been associated with an increased risk of colorectal cancer progression and mortality [6]. Barriers to timely colonoscopy include lack of awareness, psychological barriers, limited access to specialists, and financial constraints, all of which can negatively impact patient outcomes [7]. By implementing timely diagnostic follow-up, screening programs can maximize the benefits of early detection and intervention, ultimately reducing the burden of colorectal cancer [8].

However, despite well documented performance metrics, a significant research gap remains in understanding how many patients with positive Cologuard® tests follow up with the recommended colonoscopy. The objective of this study is to assess whether patients who receive a positive Cologuard® test undergo a timely follow-up colonoscopy, which is essential for confirming the presence of colorectal cancer or precancerous lesions. By analyzing patient data, and potential barriers to timely follow-up, this study aims to identify gaps in adherence and areas for improvement.