**3. Physiologic and bowel motility changes following cardiac surgery**

Despite significant hemodynamic implications of cardiac surgery, the effects on gastrointes‐ tinal system function are only modest at best. It is important to note that cardiopulmonary bypass impairs small intestinal transport and increases gut permeability, especially when pump times exceed 100 minutes [13]. Intestinal absorption also appears to be affected in car‐ dio-thoracic surgical patients [14].

**Figure 1.** Postoperative ileus following thoracoscopic right upper lobe resection. The patient improved markedly fol‐ lowing 5 days of therapy consisting of nasogastric suction, electrolyte correction and bowel rest.

The incidence of ileus (Figure 1) in cardio-thoracic surgical patients is between 1-2% [15]. Ileus is among the more common complications following cardio-thoracic procedures [16]. Various forms of ileus following CTS constitute approximately 10% of GIC [4]. Gastrointesti‐ nal motility dysfunction following cardio-thoracic procedures can take a number of clinical manifestations, from isolated gastric distention to prolonged bowel dysfunction [9]. It is im‐ portant to note that the appearance of clinically significant new ileus, especially when ac‐ companied by severe abdominal pain, may indicate a more serious underlying problem such as mesenteric ischemia or pancreatitis [15]. Mandatory perioperative fasting, the effect of anesthetic agents, and decreased patient mobility during immediate postoperative recov‐ ery, all contribute to temporary intestinal dysfunction, which in the vast majority of cases regresses automatically after the initiation of enteral intake. In a small proportion of patients the ileus persists past the fourth postoperative day, requiring the use of suppositories, ene‐ mas, and pro-motility agents (i.e., metaclopramide, erythromycin) to facilitate clinical reso‐ lution [17, 18]. In addition, the use of opioids has to be minimized due to the inhibitory effect of these analgesic agents on bowel motility [19]. The abovementioned measures, in conjunction with close clinical monitoring and normalization of serum electrolyte concentra‐ tions, are usually successful in restoring or improving intestinal function [20]. Cases that re‐ main unresponsive are treated with a course of nasogastric suction, which should be continued until the return of bowel function.
