volvulus
    n 1: abnormal twisting of the intestines (usually in the area of
         the ileum or sigmoid colon) resulting in intestinal
         obstruction

Volvulus \Vol"vu*lus\, n. [NL., fr. L. volvere to turn about, to
   roll.] (Med.)
   (a) The spasmodic contraction of the intestines which causes
       colic.
   (b) Any twisting or displacement of the intestines causing
       obstruction; ileus. See Ileus.
       [1913 Webster]