Some of the GIT causes of colic are: 1  Impactions (often caused by dry feed packing into certain parts of the GIT, which impedes or blocks the flow of GI content) 2  Spasmodic colic (increased motility of the GIT) 3  Gaseous distension.  Ulceration of the 1  stomach. Displacements of a portion.  Twists (torsion) of part of the GIT.