Source : Webster's Revised Unabridged Dictionary (1913)

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}.

Source : WordNet®

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