Metabolic and Nutritional Issues after Lower Digestive Tract Surgery: The Important Role of the Dietitian in a Multidisciplinary Setting

Abstract

Many patients undergo small bowel and colon surgery for reasons related to malignancy, inflammatory bowel disease (IBD), mesenteric ischemia, and other benign conditions, including post-operative adhesions, hernias, trauma, volvulus, or diverticula. Some patients arrive in the operating theatre severely malnourished due to an underlying disease, while others develop complications (e.g., anastomotic leaks, abscesses, or strictures) that induce a systemic inflammatory response that can increase their energy and protein requirements. Finally, anatomical and functional changes resulting from surgery can affect either nutritional status due to malabsorption or nutritional support (NS) pathways. The dietitian providing NS to these patients needs to understand the pathophysiology underlying these sequelae and collaborate with other professionals, including surgeons, internists, nurses, and pharmacists. The aim of this review is to provide an overview of the nutritional and metabolic consequences of different types of lower gastrointestinal surgery and the role of the dietitian in providing comprehensive patient care. This article reviews the effects of small bowel resection on macronutrient and micronutrient absorption, the effects of colectomies (e.g., ileocolectomy, low anterior resection, abdominoperineal resection, and proctocolectomy) that require special dietary considerations, nutritional considerations specific to ostomized patients, and clinical practice guidelines for caregivers of patients who have undergone a surgery for local and systemic complications of IBD. Finally, we highlight the valuable contribution of the dietitian in the challenging management of short bowel syndrome and intestinal failure.

Keywords: D-lactic acidosis; IBD; IF-associated liver disease; abdominoperineal resection; colectomy; dietitian; enteral nutrition; health costs; home parenteral nutrition; intestinal failure (IF); intestinal transplantation; low anterior resection; malnutrition; metabolism; micronutrients; nutrition assessment; nutritional deficiencies; proctocolectomy; refeeding syndrome; short bowel syndrome.

Figure 6

Factors influencing the development of IFALD [79,80,81,82].

Figure 7

Pathogenesis of refeeding syndrome. Phase 1: the effects of starvation [83,86].

Figure 8

Pathogenesis of refeeding syndrome. Phase 2: Clinical and metabolic consequences of non-cautious re-feeding [83,86].

Figure 1

Patients who have undergone an intestinal resection may suffer from deficiencies of micronutrients/vitamins and minerals (which, in small proportions, are essential to preserve life). For this reason, these patients should be followed and monitored long term for deficiencies of iron, albumin, vitamin B12, erythrocyte folate, vitamin D3, biotin, thiamine, riboflavin, copper, selenium, zinc, and magnesium. The levels of fat-soluble vitamins may be altered due to alterations in transporter proteins, which, like albumin, decrease in systemic inflammatory states. Yellow frames indicate sites of absorption of nutrients in the intestine.

Figure 2

Dietary advice for ostomy patients. This figure summarizes the key considerations that are most likely to improve the nutritional status, symptoms, and quality of life in these patients. It is worth emphasizing that the nutritional status of these individuals also depends on their underlying disease state (e.g., IBD or a malignancy) characterized by periods of remission and exacerbation. Thus, the best approach for the comprehensive care of a patient with an ostomy is to provide a multidisciplinary team, including a dietitian with ample expertise in surgical nutrition.

Figure 3

List of foods that contribute to the deterioration of the health-related quality of life of ostomized patients by causing an unpleasant odor, irritation of the peristomal skin, or increased output of fluid through the stoma.

Figure 4

Key points in the peri-operative nutritional management of patients with IBD [50].

Figure 5

Factors influencing the pathophysiology of SBS. SBS: short bowel syndrome.

Figure 9

The management of patients with chronic IF requires an interdisciplinary approach through management by intestinal rehabilitation centers as the standard of care. This figure shows the team members involved in the overall care of these patients [93].

Figure 10

Essential strategic issues for the management of SBS and IF.

Figure 11

Functions of the dietitian in the nutritional assessment and follow-up of the patient with SBS [91,95]. PN: parenteral nutrition; EN: enteral nutrition; IFALD: IF-associated liver disease; and RS: re-feeding syndrome.

Figure 12

Key points in the management of specific complications associated with SBS. * SBS leads to gastrointestinal losses of magnesium. Hypomagnesaemia (mainly if Mg < 1.5 mg/dL) often leads to genuine hypocalcemia by blocking parathormone secretion and promoting parathormone resistance. Hence, the importance of correcting hypomagnesemia so as not to aggravate metabolic osteopat.