Changes

Colonic impaction is intractable constipation which can occur in all species, including the dog and cat. There are hardened faeces in the colon and a delayed or failure of faecal passage. The slower transit time allows more salt and water to be reabsorbed, leaving drier faeces in the colon which are more difficult to pass. Peristalsis may increase initially but is then significantly reduced or even absent due to chronic distension and smooth muscle degeneration.

Colonic impaction is intractable constipation which can occur in all species, including the dog and cat. There are hardened faeces in the colon and a delayed or failure of faecal passage. The slower transit time allows more salt and water to be reabsorbed, leaving drier faeces in the colon which are more difficult to pass. Peristalsis may increase initially but is then significantly reduced or even absent due to chronic distension and smooth muscle degeneration.

Chronic cases may progress to Obstipation, the faeces become so hard and dry that defecation is no longer possible and ultimately there is secondary degeneration of the colonic musculature.

Chronic cases may progress to Obstipation, the faeces become so hard and dry that defecation is no longer possible and ultimately there is secondary degeneration of the colonic musculature.

==Signalment==

==Signalment==

Animals most commonly affected depend on the cause of the impaction.  

Animals most commonly affected depend on the cause of the impaction. Significant risk factors include metabolic disease causing dehydration, inapproaprate diet, and drug therapy affecting gastrointestinal motility such as anticholinergics. 

==Diagnosis==

==Diagnosis==