TORSION OF THE DOUBLE COLON 253 



tines is free from all blame in the production of these lesions. 

 It is easier to understand a twist of the small intestine apart 

 from the muscular action than it is to understand displace- 

 ment or actual twist of the large intestine. A loop or coil of 

 small intestine may be so distended by gas or ingesta as to 

 become twisted, but it is more difficult to imagine either of 

 these conditions producing twist or displacement of the large 

 intestines, and it becomes a quesion, as we have previously 

 said, how far the action of the muscular bands of tlie bowel 

 may have a contributing influence. That great force is 

 necessary is undoubted, bearing in mind the difficulty, if not 

 impossibihty, of restoring the parts to their position post- 

 mortem, or endeavouring after death to reproduce the 

 lesions experimentally.' 



Causes. — A great deal has been written regarding the 

 causation of torsion of the double colon. On first reading, 

 much of it may appear pure theorizing. It is theory, 

 however, based on what is known of the anatomy of the 

 bowel, and plausible, not only to the extent of being 

 possible, but extremely probable. 



In the first place it seems to be a fact that displace- 

 ments of the colon occur much more frequently in animals 

 of the heavy or lorry type than in those of lighter breeds. 

 And this fact is easy of explanation. The comparatively 

 more voluminous build of the bowel in the larger breeds, 

 and the fact that the colon is so largely filled with water 

 and often with abnormal quantities of indigestible food, 

 are factors that tend first to tympanitic conditions and 

 later to displacement. That the colic loop in particular 

 should be liable to displacement is readily explained 

 when we remember (a) the variation in size of its com- 

 ponent parts (notably the small dimensions of the third 

 portion as compared with the second), and (b) the fact of 

 its extremely free and unattached position in the abdomen. 



As I have explained in a previous chapter, ' We have 

 here a bowel several feet in length, of voluminous build, 



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