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.

In 2016, ESPEN published the guideline for Chronic Intestinal Failure (CIF) in adults. An updated version of ESPEN guidelines on CIF due to benign disease in adults was devised in order to incorporate new evidence since the publication of the previous ESPEN guidelines.

The grading system of the Scottish Intercollegiate Guidelines Network (SIGN) was used to grade the literature. Recommendations were graded according to the levels of evidence available as A (strong), B (conditional), 0 (weak) and Good practice points (GPP). The recommendations of the 2016 guideline (graded using the GRADE system) which were still valid, because no studies supporting an update were retrieved, were reworded and re-graded accordingly.

The recommendations of the 2016 guideline were reviewed, particularly focusing on definitions, and new chapters were included to devise recommendations on IF centers, chronic enterocutaneous fistulas, costs of IF, caring for CIF patients during pregnancy, transition of patients from pediatric to adult centers. The new guideline consist of 149 recommendations and 16 statements which were voted for consensus by ESPEN members, online in July 2022 and at conference during the annual Congress in September 2022. The Grade of recommendation is GPP for 96 (64.4%) of the recommendations, 0 for 29 (19.5%), B for 19 (12.7%), and A for only five (3.4%). The grade of consensus is "strong consensus" for 148 (99.3%) and "consensus" for one (0.7%) recommendation. The grade of consensus for the statements is "strong consensus" for 14 (87.5%) and "consensus" for two (12.5%).

It is confirmed that CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for the underlying gastrointestinal disease and to provide HPN support. Most of the recommendations were graded as GPP, but almost all received a strong consensus.

A high-output stoma (HOS) or fistula is when small bowel output causes water, sodium and often magnesium depletion. This tends to occur when the output is >1.5 -2.0 L/24 hours though varies according to the amount of food/drink taken orally. An HOS occurs in up to 31% of small bowel stomas. A high-output enterocutaneous fistula may, if from the proximal small bowel, behave in the same way and its fluid management will be the same as for an HOS. The clinical assessment consists of excluding causes other than a short bowel and treating them (especially partial or intermittent obstruction). A contrast follow through study gives an approximate measurement of residual small intestinal length (if not known from surgery) and may show the quality of the remaining small bowel. If HOS is due to a short bowel, the first step is to rehydrate the patient so stopping severe thirst. When thirst has resolved and renal function returned to normal, oral hypotonic fluid is restricted and a glucose-saline solution is sipped. Medication to slow transit (loperamide often in high dose) or to reduce secretions (omeprazole for gastric acid) may be helpful. Subcutaneous fluid (usually saline with added magnesium) may be given before intravenous fluids though can take 10-12 hours to infuse. Generally parenteral support is needed when less than 100 cm of functioning jejunum remains. If there is defunctioned bowel in situ, consideration should be given to bringing it back into continuity.

Severe short bowel syndrome (SBS) is a major cause of chronic (Type 3) intestinal failure (IF) where structural and functional changes contribute to malabsorption and risk of micronutrient deficiencies. Chronic IF may be reversible, depending on anatomy and intestinal adaptation, but most patients require long-term nutritional support, generally in the form of parenteral nutrition (PN). SBS management begins with dietary changes and pharmacologic therapies taking into account individual anatomy and physiology, but these are rarely sufficient to avoid PN. New hormonal therapies targeting intestinal adaptation hold promise. Surgical options for SBS including intestinal transplant are available, but have significant limitations. Home PN (HPN) is therefore the mainstay of treatment for severe SBS. HPN involves chronic administration of macronutrients, micronutrients, fluid, and electrolytes via central venous access in the patient's home. HPN requires careful clinical and biochemical monitoring. Main complications of HPN are related to venous access (infection, thrombosis) and metabolic complications including intestinal failure associated liver disease (IFALD). Although HPN significantly impacts quality of life, outcomes are generally good and survival is mostly determined by the underlying disease. As chronic intestinal failure is a rare disease, registries are a promising strategy for studying HPN patients to improve outcomes.

After massive small-intestinal resection or combined small-intestinal and colonic resection, diarrhea with resulting dehydration, electrolyte abnormalities, and malnutrition occur. Many patients become dependent on IV fluids and nutrition. An adaptation process manifested clinically by decreased diarrhea and improved nutrient absorption according to decreased parenteral nutrition and fluid requirements has been noted to occur over time. In some patients, adaptation is inadequate and may require special techniques to enhance and augment this process. This is a case of a 52-year-old woman who experienced increased stoma output 1 week after major intestinal resection, resulting in dehydration. She required IV fluids in order to maintain hydration. After the initiation of an intestinal rehabilitation program, which included modified diet, soluble fiber, oral rehydration solution (ORS), and medications, IV fluids were successfully weaned off in 3 months. She continues not to receive IV fluids and continues to follow the intestinal rehabilitation plan.

Chronic Intestinal Failure (CIF) is the long-lasting reduction of gut function, below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth. CIF is the rarest organ failure. Home parenteral nutrition (HPN) is the primary treatment for CIF. No guidelines (GLs) have been developed that address the global management of CIF. These GLs have been devised to generate comprehensive recommendations for safe and effective management of adult patients with CIF.

The GLs were developed by the Home Artificial Nutrition & Chronic Intestinal Failure Special Interest Group of ESPEN. The GRADE system was used for assigning strength of evidence. Recommendations were discussed, submitted to Delphi rounds, and accepted in an online survey of ESPEN members.

The following topics were addressed: management of HPN; parenteral nutrition formulation; intestinal rehabilitation, medical therapies, and non-transplant surgery, for short bowel syndrome, chronic intestinal pseudo-obstruction, and radiation enteritis; intestinal transplantation; prevention/treatment of CVC-related infection, CVC-related occlusion/thrombosis; intestinal failure-associated liver disease, gallbladder sludge and stones, renal failure and metabolic bone disease. Literature search provided 623 full papers. Only 12% were controlled studies or meta-analyses. A total of 112 recommendations are given: grade of evidence, very low for 51%, low for 39%, moderate for 8%, and high for 2%; strength of recommendation: strong for 63%, weak for 37%.

CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for both the underlying gastrointestinal disease and to provide HPN support. The rarity of the condition impairs the development of RCTs. As a consequence, most of the recommendations have a low or very low grade of evidence. However, two-thirds of the recommendations are considered strong. Specialized management and organization underpin these recommendations.

A patient with a jejunostomy 100 cm from the duodeno-jejunal flexure, following surgery for Crohn's disease, had needed parenteral fluids at home for 14 years because of a negative intestinal balance of sodium. Measurements were made of her oral intake and intestinal output during study periods each of 2 days. Loperamide 4 mg QDS, codeine phosphate 60 mg QDS and both together put her into positive intestinal fluid balance but sodium balance remained negative. Both drugs used together were more effective than either used alone. Ranitidine 300 mg BD made no significant difference to her intestinal output. 1 litre of a glucose-electrolyte solution (120 mmol sodium) sipped during the day resulted in sodium balance, but only with the addition of loperamide and codeine phosphate was positive sodium balance achieved (mean 44 mmol/day). This therapy allowed her to dispense with parenteral fluids which have been stopped for the last year.

Undernutrition as well as specific nutrient deficiencies has been described in patients with Crohn's disease (CD), ulcerative colitis (UC) and short bowel syndrome. In the latter, water and electrolytes disturbances may be a major problem. The present guidelines provide evidence-based recommendations for the indications, application and type of parenteral formula to be used in acute and chronic phases of illness. Parenteral nutrition is not recommended as a primary treatment in CD and UC. The use of parenteral nutrition is however reliable when oral/enteral feeding is not possible. There is a lack of data supporting specific nutrients in these conditions. Parenteral nutrition is mandatory in case of intestinal failure, at least in the acute period. In patients with short bowel, specific attention should be paid to water and electrolyte supplementation. Currently, the use of growth hormone, glutamine and GLP-2 cannot be recommended in patients with short bowel.

Radiation enteritis can be challenging to diagnose and treat. We report the case of a 44-year-old woman who was diagnosed with a squamous cell carcinoma of the cervix in 1978 and treated with hysterectomy and post-operative radiotherapy. Over the next 20 years she required multiple intestinal operations resulting in short bowel syndrome. She became symptomatic of severe hypomagnesaemia which could not be corrected with oral supplementation and which required intravenous magnesium sulfate every 5-7 days for an 11-month period. However, following 25 sessions of hyperbaric oxygen therapy, she was able to discontinue intravenous magnesium and maintain her serum magnesium level with oral treatment. Her weight and stoma output improved. For over 4 years subsequent to this therapy she has not required further intravenous magnesium although has needed temporary nutritional support. Her case is complicated by vitamin A, B and D deficiencies.

Undernutrition as well as specific nutrient deficiencies have been described in patients with Crohn's disease (CD), ulcerative colitis (UC) and short bowel syndrome (SBS). The present guideline gives evidence-based recommendations for the indication, application and type of formula of enteral nutrition (EN) (oral nutritional supplements (ONS) or tube feeding (TF)) in these patients. It was developed in an interdisciplinary consensus-based process in accordance with officially accepted standards and is based on all relevant publications since 1985. ONS and/or TF in addition to normal food is indicated in undernourished patients with CD or CU to improve nutritional status. In active CD EN is the first line therapy in children and should be used as sole therapy in adults mainly when treatment with corticosteroids is not feasible. No significant differences have been shown in the effects of free amino acid, peptide-based and whole protein formulae for TF. In remission ONS is recommended only in steroid dependent patients in CD. In patients with SBS TF should be introduced in the adaptation phase and should be changed with progressing adaptation to ONS in addition to normal food.

The number of enteral diets has increased from a handful in the 1970s to over 100 at present. These can be classified as polymeric, chemically defined, disease-specific, and specialized diets, as well as oral dietary supplements. The properties, indications, pros and cons for the use of these diets are outlined in an effort to assist clinicians in their selection.

Loss of water during enteral nutrition following massive intestinal resection may be severe. Low osmolality of oral rehydration solutions has recently been shown to mediate an increase in water absorption.

To evaluate the effect of osmolality of a nutrient solution on the intraluminal duodenojejunal water flow, and the net absorption rates of total nitrogen and carbohydrate.

Eight healthy volunteers with a mean age of 27 (range 25-29) years participated in the study. Enteral nutrition (17% protein, 59% carbohydrate, 24% lipid plus 5 g/L PEG 4000) was infused (5 mL/min 2.64 kcal/min) into the descending duodenum either as a hypotonic (160 mOsmol/kg) or as an isotonic solution in a random order. Intestinal samples were aspirated 20 and 45 cm distally to the infusion point.

Intraluminal water flow rates were significantly lower with the hypotonic solution than with the isotonic solution, both in the duodenum (4.9 +/- 0.3 vs. 6.7 +/- 0.5 mL/min; P < 0.02) and the upper jejunum (3.0 +/- 0.1 vs. 3.9 +/- 0.2 mL/min; P < 0.005). The net absorption rates of total nitrogen and carbohydrate were similar with both solutions.

Low osmolality of a nutrient solution decreases intraluminal water flow rates in the upper intestine without affecting the absorption rates of total nitrogen and carbohydrate. Compared with an isotonic solution, the use of a hypotonic solution might lower the water loss in patients with extensive short bowel intestinal resection.

To compare the effects of a standard oral rehydration solution with a polymeric glucose isotonic solution enriched with glutamine on water and sodium absorption in the short bowel.

Six patients with high jejunostomy were tested in a random order on 2 consecutive days with the standard solution (20 g/L glucose, 94 mmol/L sodium, 292 mOsm/kg osmolality) and a solution containing maltodextrins (18 g/L Glucidex 12; hydrolysis of 18 g of Glucidex 12 yields 20 g glucose) enriched with 14.6 g/L of glutamine (94 mmol/L sodium, 282 mOsm/kg osmolality). Solutions were administered via a naso-gastric tube at a rate of 2 mL/min. Jejunal effluent for each solution was collected during an 8-h period, after a 14-h equilibrium period.

The net 8-h fluid absorption was not significantly different between the standard solution and the solution with glutamine (333 +/- 195 and 213 +/- 251 mL, respectively (mean +/- S.E.M.)). Net sodium absorption was higher for the standard solution than for the solution with glutamine (15 +/- 15 vs. 2 +/- 20 mmol, P < 0.05). The rate of glucose absorption was not different between the solutions.

The replacement of glucose by maltodextrins and the addition of glutamine to the standard oral rehydration solution, without changing its sodium content or osmolality, results in a reduction of sodium absorption in the short-bowel syndrome.

This article discusses the management of short bowel syndrome from the time of intestinal resection until the patient either recovers free of supplemental parenteral and enteral nutrition or progresses to the point of needing intestinal transplantation. The importance of aggressive use of enteral feedings is emphasized, especially in relation to the process of intestinal adaptation. An approach to the various complications of short bowel syndrome, especially small bowel bacterial overgrowth, is discussed. Surgical options short of transplantation also are described. Intestinal transplantation and its present and future roles in the management of patients with short bowel syndrome are discussed.

A shortened small intestine may end at a stoma or be anastomosed to the colon. Patients with a jejunostomy, but not those with a colon, lose large amounts of sodium. The intake and absorption of sodium can be increased by sipping a sodium-glucose solution; stomal loss can be reduced by restricting water or low-sodium drinks. If a stoma is situated less than 100 cm along the jejunum, a constant negative sodium balance may necessitate parenteral saline supplements. Gastric anti-secretory drugs or a somatostatin analogue reduce jejunostomy losses in such patients but do not restore a positive sodium balance. Loperamide or codeine phosphate benefit some patients. Magnesium deficiency can usually be corrected by oral magnesium oxide supplements. An elemental or hydrolysed diet is not beneficial. Patients with a jejunostomy can maintain a normal diet without fat reduction. When the colon is present, unabsorbed carbohydrate is fermented to absorbable short chain fatty acids. Unabsorbed long chain fatty acids and bile salts cause watery diarrhoea and increased colonic oxalate absorption with hyperoxaluria. Such patients benefit from a high carbohydrate, low-fat and low-oxalate diet. Parenteral nutrition is needed only by the few patients unable to maintain health or avoid socially disabling diarrhoea despite these measures.

The management of short bowel syndrome requires long-term nutritional support and monitoring, medication, and occasionally additional surgical procedures. Constant attention is required to ensure adequate adaptation of the gut. This article reviews the normal function of the small bowel, adaptation following resection, total parenteral and enteral nutrition, and the role of adjunctive surgical procedures in the management of short bowel syndrome.

The aim of this study was to determine whether fluid homeostasis could be maintained by using a hypo-osmolar (200 to 221 mosmol/kg), relatively low-sodium (50 to 52 mmol/liter) solution that contained a glucose polymer in a 54-year-old patient with high ileostomy output attributed to short-gut syndrome and resultant prerenal azotemia. Sequential balance studies were performed to assess stool and urinary output, stool fat, and urinary electrolytes initially during intravenous rehydration and subsequently during administration of the necessary fluids and nutrients exclusively by oral supplementation. The additional effects of high-fat and low-fat diet, loperamide hydrochloride, and octreotide acetate were evaluated. When the patient sipped a hypo-osmolar oral rehydration solution while she was awake during the day and received a high dose of loperamide and a 40-g fat, disaccharide-free diet, salt and water homeostasis was maintained. The addition of octreotide did not substantially enhance fluid balance; rather, it increased fecal fat and fluid losses from the small bowel. Thus, hypo-osmolar polymeric glucose solutions maintain fluid homeostasis in patients with the short-gut syndrome. In such patients, simple balance studies are useful for assessing the absorptive capacity of the residual intestine, for developing an optimal individualized treatment, and for eliminating the need for costly, long-term home parenteral nutrition.

Six patients with jejunostomies and residual jejunal lengths of 105 to 250 cm took the same food and water each day for eight study days. In random order, three methods of salt replacement were tested, each over 48 hours, against a period without added salt. During the three test periods the patients took 120 mmol of sodium chloride daily, as salt in gelatine capsules, as an isotonic glucose electrolyte (280 mOsmol/kg; 30 kcal) solution, and as a glucose polymer (Maxijul) solution (280 mOsmol/kg; 200 kcal). The daily stomal output remained constant for each patient during the four test periods but varied between patients from 0.60 to 2.84 kg (daily intestinal fluid balance 0.74-2.61 kg). Without a salt supplement, three patients lost more sodium from the stoma than they took in by mouth (-25, -94, and -101 mmol/day) and the mean sodium balance for all six subjects was -16 mmol (range -101 to 79) daily. Extra salt was absorbed with each form of supplement (p less than 0.05); no patient with the glucose electrolyte solution (mean 96, range 0 to 226 mmol), but one patient with the glucose-polymer solution (mean 96, range -25 to 164 mmol) and two with the salt capsules (mean 66, range -8 to 145 mmol) were in negative balance. Two patients vomited with the salt capsules. There was only a small increase in energy absorption (mean 115 kcal) with the glucose polymer solution compared with the glucose electrolyte solution. A sipped glucose electrolyte solution seems to be the optimal mode of sodium replacement in patients with a high output jejunostomy.

This comprehensive bibliography is intended to enhance the education of the practitioner, student, and academician in the area of parenteral nutrition. This bibliography is not all-inclusive but serves as an update from the original published in 1983. Of particular note in this work is the addition of topics that reflect a growing interest in medical specialties with regard to patient nutritional status and support.

Jejunostomy losses of Na+ and water during enteral nutrition after massive intestinal resection may be severe. We have attempted to analyse this practical problem by using an in vivo perfusion technique in healthy volunteers to study Na+, water and nutrient absorption from a short (25 cm) segment of jejunum during perfusion of an isotonic solution of the elemental diet Vivonex. Further solutions made from the amino acid and carbohydrate components of Vivonex were also perfused in part I of the study in order to determine the causes of the marked Na+ and water secretion seen during Vivonex perfusion. Low initial Na+ concentration was found to be the major determinant of net Na+ secretion, initial Na+ concentration correlating significantly with Na+ absorption (r = 0.95, n = 7 p less than 0.001). Water absorption correlated with net absorption of NaCl (r = 0.82, n = 7 p less than 0.01). There was, however, a better correlation with total absorption of NaCl plus amino acids (r = 0.99, n = 7, p less than 0.01). In part II of the study separate isotonic solutions of NaCl, glucose, and the polymeric diet, Ensure were also studied. Net sodium secretion occurred during glucose and Ensure perfusion, as predicted from their low Na+ concentration. Owing to rapid sucrose absorption from Ensure there was substantial luminal disappearance of osmotically active particles and hence marked water absorption, which was accurately predicted using the regression equation for water absorption derived in part I, substituting sucrose absorption for amino acid absorption. We conclude that the marked Na+ and water secretion observed during Vivonex perfusion is not a unique property of this amino acid based diet but is due to its low Na+ content.

Commonly used oral electrolyte solutions are based on glucose, or sucrose, and 90 mM Na+. We had been disappointed with the ability of such solutions to improve Na+ absorption in patients with extensive resection of distal small bowel. Therefore, we tested the effect on net Na+ and water transport of combinations of different carbohydrates (glucose, sucrose, and glucose polymers) and NaCl in the rat duodenojejunum. Absorption was measured under steady-state conditions in unanesthetized animals which were infused with a different combination every hour for up to 5 hr. Of the various combinations, 10 mM glucose polymer (equivalent to 56 mmol of glucose as glucose oligosaccharides), or 60 mM glucose promoted net Na+ absorption from 120 mM NaCl and 20 mM KCl, but the glucose polymer infusate promoted more rapid water absorption than did the infusate containing glucose. The infusate of 10 mM glucose polymer in saline was initially hypotonic (276 mosmol/kg), but it became isotonic (298 mosmol/kg) as the glucose polymer was hydrolyzed during its passage through the duodenojejunum. In contrast, an infusate of 60 mM sucrose with 120 mM NaCl and 20 mM KCl remained hypertonic (320 mosmol/kg), and it did not promote water and Na+ absorption by the duodenojejunum. The efficacy of 10 mM glucose polymer with 120 mM NaCl should be tested in patients with short-bowel syndrome due to distal bowel resection.

Five trained ileostomates completed a marathon in a cool environment without ill effect. During the race, the ileostomy losses of sodium (1.0-2.7 mmol.h-1) and of water (9.2-19 ml.h-1) were small, but urinary excretion of sodium was very low (0.2-0.75 mmol.h-1) despite drinking a combination of water and glucose-electrolyte solution. The concentration of potassium in the ileostomy discharge tended to increase, also suggesting a sodium retaining state. Healthy ileostomates after suitable training are successful marathon runners, but the prevalence of mild salt depletion in ileostomates generally suggests that it may be advisable for them to take only glucose-electrolyte solutions when competing at any ambient temperature or when preparing for a marathon which is to take place in a warm environment.