To answer this question I usually refer people to a Spoiled Ratten Rattery article that goes into great detail about this subject. Contrary to what some people think, not all rats with blazes are at risk for MC. My rats come from dalmatia...
http://www.paperheartrats.com/faq.html
Your veterinarian will perform a complete physical examination, including a complete neurological exam. Abdominal palpitation will reveal a hard & full colon.
http://www.cat-world.com.au/MegacolonInCats.htm
Toxic megacolon is the clinical term for an acute toxic colitis with dilatation of the colon.
http://www.emedicine.com/med/topic1418.htm
n A result of a chronic refusal to defecate, usually occurring in children who are psychotic or mentally retarded.
http://www.answers.com/topic/acquired-megacolon
n Caused by the absence of autonomic ganglia in the smooth muscle wall of the colon.
http://www.answers.com/topic/congenital-megacolon
congenital megacolon; Hirschsprung's disease
http://www.audioenglish.net/dictionary/congenital_megac...
Toxic Megacolon Risk Factors. This is a complication of inflammatory bowel disease, such as ulcerative colitis and Crohn's disease, and some infections of the colon. Other forms of megacolon exist and can be congenital (present since birth)...
http://www.ask.com/web?q=what%20causes%20toxic%20megaco...