As described earlier, the mesentery of the ascending colon fuses with the posterior abdominal wall. Due to the loss of mesentery the ascending colon and upper end of the cecum become fixed to the posterior abdominal wall. The appendix and
lower end of the cecum, however, retain their short mesenteries and have a very limited amount of mobility. In 10°/* of the people the cecum possesses an unusual amount of freedom. This condition, termed mobile cecum, results from incomplete fixation of the ascending colon which leads to persistence of a portion of the mesocolon. This is clinically significant for two reasons: (1) due to the mobile cecum the position of the appendix becomes highly variable, which may produce difficulties for surgeon during an operation for appendicitis, and (2) a very mobile cecum may undergo twisting and volvulus formation.