Watershed area between SMA and IMA which commonly result in ischemia is?

There are several weak points in the colonic blood supply, known as watershed areas, which result from incomplete anastomoses of the marginal aeries.The two most common points are:- Griffith's point at the splenic flexure and- Sudeck's point at the rectosigmoid junction.Rectosigmoid junction is the watershed territory between IMA and the internal iliac aery.