Crohn's disease can be seen in -
• Chronic, transmural inflammatory disease of the GIT for which the cause is unknown.
• Can involve any part of the alimentary tract from the mouth to the anus but most commonly affects the small intestine and colon
• Involvement of both large and small intestine: 55%
• Involvement of only small intestine: 30%
• Involvement of only large intestine: 15%
• Crohn’s disease primarily attacks young adults in the 2nd and 3rd decades of life.
• More common in smokers and urban dwellers
• Two genders are affected equally with strong familial association
• Upper GI Crohn’s disease is most frequently found in the gastric antrum and duodenum.
• In patients with colonic disease, rectal sparing is characteristic.
Etiology: Unknown
• Infectious agents proposed as potential causes: Mycobacterium paratuberculosis and measles virus.
• The identification in 2001 of the CARD-15/NOD2 mutation (on chromosome 16q, also known as IBD-1 locus) provided the first definitive genetic link to the condition and is relatively specific for Crohn’s disease.
Jejunum only
Colon only
Terminal ileum and right side
Mouth to anus