Watershed zone of large intestine ?

There are areas of colon with poor blood supply resulting from incomplete anastomosis of marginal aeries. These are watershed areas of colon and include :Splenic flexure (Griffith point) : Watershed area between superior mesenteric aery and inferior mesenteric aery.Rectosigmoid junction (Sudeck's point) : Watershed zone between inferior mesenteric aery and internal iliac aery.