This is a picture showing the small intestine, pancreas and liver.  They are all important in digesting food products and absorbing the nutrients.  Notice the size of the liver compared to the pancreas.  Both organs secrete products into the large intestine.
 
 

    This a picture of the junction between the small intestine and the large intestine.  There is a specialized structure called the cecum at this junction.  The cecum are large to help break down plant products that the duck might consume.