Lower gastrointestinal bleeding (LGIB) can result in serious adverse events. Appropriate risk stratification of LGIB patients can improve their care. Previous risk scores to identify severe LGIB patients have limitations, therefore we developed clinical decision tool to accurately identify LGIB patients presenting to the emergency department (ED) who are at risk for 30-day adverse outcomes that would overcome these limitations. We conducted a health records review and compared two methods of regression analysis on our data in order to develop a clinical decision tool. We identified five risk factors that have a high sensitivity and good predictive value for identifying low risk LGIB patients: age ≥ 75 years, INR ≥2.0, hemoglobin ≤ 100 g/l, ongoing bleeding in the ED and a medical history of colorectal polyps. Future, large, prospective studies should be done to validate the results, after which implementation studies should be conducted.