Although sub-total colectomy is an effective way of correcting megacolon, removal of majority of the colon has the potential to cause metabolic effects in the animal. For example, the colon normally functions to absorb water. This is achieved by the creation of an osmotic gradient by active sodium absorbtion. Additionally, extracellular potassium is lost and bicarbonate ions are exchanged for chloride ions in the colon. It could therefore be implied that sub-total colectomy disrupts water and electrolyte homeostasis, but paradoxically cats undergoing sub-total colectomy have been found to show no clinical evidence of abnormal bowel function<sup>6</sup>. However, other, non-clinical changes were found: small intestinal enterocytes and villi were increased in height, the absorptive area of the small intestinal muscosa was increased, serum cobalamin and faecal sodium were increased and faecal potassium was low. The significance of these results is unknown. | Although sub-total colectomy is an effective way of correcting megacolon, removal of majority of the colon has the potential to cause metabolic effects in the animal. For example, the colon normally functions to absorb water. This is achieved by the creation of an osmotic gradient by active sodium absorbtion. Additionally, extracellular potassium is lost and bicarbonate ions are exchanged for chloride ions in the colon. It could therefore be implied that sub-total colectomy disrupts water and electrolyte homeostasis, but paradoxically cats undergoing sub-total colectomy have been found to show no clinical evidence of abnormal bowel function<sup>6</sup>. However, other, non-clinical changes were found: small intestinal enterocytes and villi were increased in height, the absorptive area of the small intestinal muscosa was increased, serum cobalamin and faecal sodium were increased and faecal potassium was low. The significance of these results is unknown. |