All reported epidemiological statistics on rotational abnormalities are likely to dramatically underestimate the true prevalence, given that some people with incomplete rotation remain asymptomatic and are never diagnosed, and some may present later in life (e.g., in adulthood).[1]Flynn-O'Brien KT, Rice-Townsend SE. Structural anomalies of the gastrointestinal tract. In: Gleason CA, Juul SE, eds. Avery's Diseases of the Newborn. 11th ed. Philadelphia, PA: Elsevier;2024:897-912. Of patients with malrotation who become symptomatic, 50% to 75% do so in the first month and about 90% within the first year of life.[2]Gross RE. Malrotation of the intestine and colon. In: Gros RE, ed. The surgery of infancy and childhood. Philadelphia, PA: WB Saunders; 1953:192. Symptomatic malrotation is thought to occur in 1 of every 6000 live births; however, this figure may be an underestimate and could be as high as 2.86 per 10,000 live births.[3]Forrester MB, Merz RD. Epidemiology of intestinal malrotation, Hawaii, 1986-99. Paediatr Perinat Epidemiol. 2003 Apr;17(2):195-200.
http://www.ncbi.nlm.nih.gov/pubmed/12675787?tool=bestpractice.com
[4]von Flüe M, Herzog U, Ackermann C, et al. Acute and chronic presentation of intestinal nonrotation in adults. Dis Colon Rectum. 1994 Feb;37(2):192-8.
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[5]Schulman J, Edmonds LD, McClearn AB, et al. Surveillance for and comparison of birth defect prevalences in two geographic areas-United States, 1983-88. MMWR CDC Surveill Summ. 1993 Mar 19;42(1):1-7.
https://www.cdc.gov/mmwr/preview/mmwrhtml/00020397.htm
http://www.ncbi.nlm.nih.gov/pubmed/8474427?tool=bestpractice.com
Rotational abnormalities have been noted as an incidental finding in 0.2% of upper gastrointestinal contrast studies.[6]Kantor JL. Anomalies of the colon: their roentgen diagnosis and clinical significance: Resume of 10 years study. Radiology. 1934;23:651-662. This denominator is also misleading, as it selects patients with certain gut symptoms given that they required such a study. Autopsy series have documented non-rotation in 0.5%.[7]Skandalakis JE, Gray SW, Ricketts R, et al. The small intestines. In: Skandalakis JE, Gray SW, eds. Embryology for surgeons, 2nd ed. Baltimore, MD: Williams & Wilkins; 1994:184.