Megaduodenum is a marked distention of the duodenum. It may be caused by a number of conditions.


Causes of megaduodenum may be classified as:

(1) obstructive

(2) nonobstructive (localized chronic intestinal pseudo-obstruction with hypoperistalsis)

(2a) myopathic

(2b) neuropathic

(2c) other


Obstructive megaduodenum:

(1) annular pancreas

(2) tumor

(3) mesenteric fibromatosis

(4) duodenal malformation (atresia, stenosis, diaphragm, other)


Myopathic megaduodenum (either due to loss of muscle cells or loss of muscle function):

(1) scleroderma

(2) amyloidosis

(3) myopathy

(4) dermatomyositis

(5) SLE

(6) myxedema

(7) injection of botulinum toxin (reversible)


Neuropathic megaduodenum:

(1) damage to myenteric plexus

(2) diabetic neuropathy

(3) congenital hypoganglionosis



(1) Ehlers-Danlos syndrome


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