Annular pancreas

An annular pancreas is a ring or collar of pancreatic tissue that abnormally encircles the duodenum (the part of the small intestine that connects to stomach).

Causes, incidence, and risk factors

Annular pancreas is thought to be caused by a malformation during the development of the pancreas, before birth. This condition may result in a narrowing of the duodenum due to constriction by the ring of pancreas.

Complete obstruction of the duodenum is often seen in newborns with this condition. However, half of the cases occur in adults. There are probably many cases that go undetected due to mild symptoms.

There is an increased incidence of peptic ulcer associated with this condition. Annular pancreas affects approximately 1 in 7,000 people.


  • Fullness after eating  
  • nausea  
  • Vomiting  
  • Feeding intolerance in newborns

Signs and tests

Signs that may indicate annular pancreas include the following:

  • Polyhydramnios (excessive amniotic fluid during pregnancy)  
  • Pancreatitis  
  • Down syndrome  
  • Other congenital gut anomalies

Tests include:


Surgical bypass of the obstructing segment of the duodenum is the usual treatment for this disorder.

Expectations (prognosis)

There is a good prognosis with surgery.


  • Peptic ulcer  
  • Perforation of the intestine due to obstruction  
  • Peritonitis

Calling your health care provider

Call for an appointment with your health care provider if you or your child develop any symptoms of annular pancreas.

Johns Hopkins patient information

Last revised: December 2, 2012
by Arthur A. Poghosian, M.D.

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