ABSTRACT: Colonic diverticula are the most common finding from colonoscopy examinations. Little is known about the distribution of colonic diverticula, which are responsible for symptomatic and costly diverticular disease. We aimed to assess the number, location, and characteristics of colonic diverticula in a large US screening population.We analyzed data from a prospective study of 624 patients (mean age, 54 years) undergoing screening colonoscopy at the University of North Carolina Hospital from 2013 through 2015. The examination included a detailed assessment of colonic diverticula. To assess the association between participant characteristics and diverticula, we used logistic regression to estimate odds ratios and 95% confidence intervals.Of our population, 260 patients (42%) had 1 or more diverticula (mean number, 14; range, 1-158). Participants with diverticula were more likely to be older, male, and have a higher body mass index than those without diverticula. The distribution of diverticula differed significantly by race. Among white persons, 75% of diverticula were in the sigmoid colon, 11% in the descending splenic flexure, 6% in the transverse colon, and 8% were in the ascending colon or hepatic flexure. In black persons 64% of diverticula were in the sigmoid colon, 8% in the descending colon or splenic flexure, 7% in the transverse colon, and 20% in the ascending colon or hepatic flexure (P = .0008). The proportion of patients with diverticula increased with age: 35% were 50 years or younger, 40% were 51-60 years, and 58% were older than 60 years. The proportion of patients with more than 10 diverticula increased with age: 8% were 50 years or younger, 15% were 51-60 years, and 30% were older than 60 years.Older individuals not only have a higher prevalence of diverticula than younger individuals, but also a greater density, indicating that this is a progressive disease. Black persons have a greater percentage of their diverticula in the proximal colon and fewer in the distal colon compared with white persons. Understanding the distribution and determinants of diverticula is the first step in preventing diverticulosis and its complications.