Angiodysplasias are responsible for approximately 6% of cases of lower gastrointestinal bleeding and 1.2% to 8% of upper gastrointestinal hemorrhages.[5]Foutch PG. Angiodysplasia of the gastrointestinal tract. Am J Gastroenterol. 1993 Jun;88(6):807-18.
http://www.ncbi.nlm.nih.gov/pubmed/8389094?tool=bestpractice.com
[7]Clouse RE, Costigan DJ, Mills BA, et al. Angiodysplasia as a cause of upper gastrointestinal bleeding. Arch Intern Med. 1985 Mar;145(3):458-61.
https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/605475
http://www.ncbi.nlm.nih.gov/pubmed/3872107?tool=bestpractice.com
Colonic angiodysplasia is the most common vascular malformation in the gastrointestinal tract, and most lesions are detected in patients ages >60 years.[5]Foutch PG. Angiodysplasia of the gastrointestinal tract. Am J Gastroenterol. 1993 Jun;88(6):807-18.
http://www.ncbi.nlm.nih.gov/pubmed/8389094?tool=bestpractice.com
Small bowel angiodysplasias are also found in a similar age group and are the most common causes of small bowel bleeding in patients over the age of 40 years.[8]Gerson LB, Fidler JL, Cave DR, et al. ACG clinical guideline: diagnosis and management of small bowel bleeding. Am J Gastroenterol. 2015 Sep;110(9):1265-87; quiz 1288.
https://journals.lww.com/ajg/fulltext/2015/09000/acg_clinical_guideline__diagnosis_and_management.10.aspx
http://www.ncbi.nlm.nih.gov/pubmed/26303132?tool=bestpractice.com
[9]Chetcuti Zammit S, Koulaouzidis A, Sanders DS, et al. Overview of small bowel angioectasias: clinical presentation and treatment options. Expert Rev Gastroenterol Hepatol. 2018 Feb;12(2):125-39.
http://www.ncbi.nlm.nih.gov/pubmed/28994309?tool=bestpractice.com
Angiodysplasias are uncommon among healthy asymptomatic people, with a prevalence of 0.83%.[10]Foutch PG, Rex DK, Lieberman DA. Prevalence and natural history of colonic angiodysplasia among healthy asymptomatic people. Am J Gastroenterol. 1995 Apr;90(4):564-7.
http://www.ncbi.nlm.nih.gov/pubmed/7717311?tool=bestpractice.com
Two percent of asymptomatic older patients have colonic angiodysplasia at autopsy.[11]Baer JW, Ryan S: Analysis of cecal vasculature in the search for vascular malformations. AJR Am J Roentgenol. 1976 Feb;126(2):394-405.
http://www.ajronline.org/doi/pdf/10.2214/ajr.126.2.394 https://www.ajronline.org/doi/10.2214/ajr.126.2.394
http://www.ncbi.nlm.nih.gov/pubmed/175709?tool=bestpractice.com
Small bowel angiodysplasia, with a 1% to 2% prevalence, accounts for 30% to 40% of patients with gastrointestinal bleeding of obscure origin, being the single most common cause of hemorrhage in this subset.[5]Foutch PG. Angiodysplasia of the gastrointestinal tract. Am J Gastroenterol. 1993 Jun;88(6):807-18.
http://www.ncbi.nlm.nih.gov/pubmed/8389094?tool=bestpractice.com
There are no documented global differences, or ethnicity or sex predominance.