DefinitionAn annular pancreas is a ring of pancreatic tissue that encircles the duodenum (the first part of the small intestine). Normally, the pancreas sits next to, but does not surround the duodenum.Causes, incidence, and risk factorsAnnular pancreas is a congenital defect, which means it is present at birth. Symptoms occur when the ring of pancreas squeezes and narrows the small intestine so that food cannot pass easily or at all.Newborns may have symptoms of complete blockage of the intestine. However, up to half of people with this condition do not have symptoms until adulthood. There are also cases that are not detected because the symptoms are mild.Conditions that may be associated with annular pancreas include:Down syndromeOther congenital gastrointestinal problemsPancreatitisExce