Lower gastrointestinal bleeding (LGIB) (hematochezia) is an important indication for colonoscopy, and may be caused by hemorrhoids, diverticulosis, and tumors. The aim of this study was to compare the endoscopic findings in the young (<50 years) versus older subjects (≥50 years) with LGIB in Nigeria. This was a retrospective study of the endoscopic findings of all adults with LGIB from January 2017 to December 2019 in Lagos, Nigeria. The records of two centers that deliver outpatient gastrointestinal endoscopic services were ploughed for biodata, presenting complaints and findings in these individuals. These data were then analyzed and are thus presented. A total of 1,774 colonoscopies performed during this period, 793 were for LGIB. Of those with LGIB, 548 (69.1%) were males, 245 (30.9%) were female, mean age was 50.7 (±14) years, and 403 (50.8%) were younger than 50 years old. The most frequent findings in patients younger than 50 years were hemorrhoids (316, 78.4%), tumors (35, 8.7%), and polyps (27, 6.7%), while in the older patients, they were hemorrhoids (259, 66.4%), tumors (74, 19%) and diverticulosis (55, 14.1%). Younger age was significantly associated with the presence of hemorrhoids (P < 0.005), while older age was significantly associated with the presence of tumors (P < 0.005) and diverticulosis (P < 0.005). Our study showed that hemorrhoids, tumors, and diverticulosis were the most common causes of LGIB in Nigerian patients - with younger age being significantly associated with hemorrhoids, and older age with tumors and diverticulosis. A third of the tumors in this study were found in younger patients. Unfortunately, this finding of such a high proportion of colorectal tumors being found in young Africans has been shown in previous reports - this work should help heighten concern and provoke further scientific probing into the phenomenon with a view to encouraging policy to help truncate its existence.