This image shows some of the details of the cat digestive system.  Leaving the stomach  through the pyloric sphincter is the small intestine where the majority of digestion and nearly all absorption occurs.  The first portion of the small intestine is called the duodenum, which receives secretions from the liver and pancreas.  The last portion of the small intestine is called the ileum, which empties into the large intestine through the ileocecal valve.  The large intestine is also divided into four regions: the colon, cecum, rectum and anal canal.  The first portion of the colon is the ascending colon.  A blind pouch called the cecum hangs just below the point at which the ileum joins the large intestine.  In humans, a twisted, coiled tube called the vermiform appendix hangs off the cecum.  Filled with lymphatic tissue, this structure can become the site of inflammation, or an appendicitis.