large intestine large intestine the large intestine, also known as the large bowel, is the last part of the gastrointestinal tract and of the digestive system in tetrapods. water is absorbed here and the remaining waste material is stored in the rectum as feces before being removed by defecation. the colon is the longest portion of the large intestine, and the terms are often used interchangeably but most sources define the large intestine as the combination of the cecum, colon, rectum, and anal canal. some other sources exclude the anal canal. large intestinefront of abdomen, showing surface markings for the liver (red), and the stomach and large intestine (blue). the large intestine is like an upside down u.detailspart ofgastrointestinal tractsystemdigestive systemarterysuperior mesenteric, inferior mesenteric and iliac arteriesveinsuperior and inferior mesenteric veinlymphinferior mesenteric lymph nodesidentifierslatincolon or intestinum crassummeshd007420ta98a05.7.01.001ta22963fma7201anatomical terminology major parts of thegastrointestinal tract upper gastrointestinal tract mouth esophagus stomach duodenum lower gastrointestinal tract small intestine jejunum ileum large intestine sigmoid colon rectum anus