Energy absorption as a measure of intestinal failure in the short bowel syndrome.

Energy absorption from a liquid test meal, intestinal transit rate and water and sodium output over a six hour period were measured in five patients with an ileostomy and 12 patients with the short bowel syndrome, five of whom were on longterm parenteral nutrition. The proportion of total energy absorbed was greatest in the ileostomists (median 87%, range 82-92%), less in short bowel patients not on parenteral nutrition (median 67%, range 59-78%, p less than 0.01) and least in the short bowel group who needed it (median 27%, range 2-63%, p less than 0.01). Transit rate was more rapid in the short bowel patients compared with the ileostomists. A close correlation was observed between percentage energy absorption and the dry weight of the stools/stoma effluent collected during the six hour test period (r = -0.99, p less than 0.001). This simple non-invasive test quantitates the degree of intestinal failure and may be of practical help in management.     

Plasma ghrelin levels in patients with short bowel syndrome

Ghrelin is a novel peptide hormone which was identified as an endogenous growth hormone secretagogue. It is mainly secreted in the stomach, but important sites of its secretion are other parts of the gastrointestinal tract. Ghrelin is thought to be involved not only in regulation of growth hormone secretion but also in regulation of food intake and nutritional status. This study was aimed to investigate the changes in plasma ghrelin levels in patients with short bowel syndrome. Twenty-four patients with malnutrition due to short bowel syndrome and eleven healthy controls were included in the study. They underwent clinical examination and assessment of plasma or serum levels of ghrelin leptin, soluble leptin receptor, IGF-I, IGFBP-1 and IGFBP-3. Plasma ghrelin levels were decreased in patients with short bowel syndrome (p<0.01). Furthermore, decreased serum levels of IGF-I (p<0.01) and IGFBP-3 (p<0.001) were found in patients with short bowel syndrome. Other laboratory differences between both groups were not significant. No relationship between ghrelin and other determined variables was found. We conclude that plasma ghrelin levels are decreased in the group of patients with short bowel syndrome. It is probably because of a decrease in the tissue mass that is able to secrete ghrelin.     

Nutritional absorption in short bowel syndrome

Eight patients with a short bowel resulting from intestinal resection and clinically stable for at least one year were studied for 10 days. The diet chosen was lactose-free with a low fiber content and contained 22% of total calories as protein, 32% as carbohydrate, and 46% as fat. Total fluid volume was kept constant, and all patients were in positive nitrogen balance. During the 10-day period, blood chemical concentrations, stool, and/or ostomy volume, urine volume, electrolyte excretion, and calorie and divalent cation absorption were measured. In addition it was determined that fluid restriction during meals did not affect these parameters. In these patients the absorptions of fat, carbohydrate, protein, and total calories were 54%, 61%, 81%, and 62%, respectively. Similarly the absorption of the divalent cations, calcium, magnesium, and zinc, were 32%, 34%, and 15%, respectively. We suggest that patients with short bowel syndrome, who have been stable for at least one year and who can tolerate oral diets, do not need to restrict fat or to separate fluids from solids during their meals. Furthermore, they should increase their oral intake to 35–40 kcal/kg ideal body weight in order to counteract their increased losses. The diet should contain 80–100 g protein/day in order to maintain a positive nitrogen balance and a large margin of safety. In addition, these patients may take oral supplementation of calcium, magnesium, and zinc to maintain divalent cation balance.This work was supported by a grant from the Ontario Ministry of Health PR. 228.     

L-thyroxine absorption in patients with short bowel

Because the exact site of thyroid hormone absorption in man is not known, we assessed the absorption of oral [125I]Na-L-T4 in patients with varying lengths of intact bowel and correlated this absorption with bowel length. Two normal subjects and five patients with surgical bowel resections, all of whom were euthyroid, were studied. Each received a tracer dose of [125I]Na-L-T4 orally, and serial samples of serum were assayed for radioactivity both with and without butanol extraction. The peak serum radioactivity in normal subjects occurred 2 h post ingestion and was 15% and 17% of the administered dose per liter serum and 11% and 13%/liter serum in butanol-extracted serum, respectively. In patients with shortened bowel, the peak radioactivity both in serum and butanol extracted serum was decreased, ranging from 2%-7% and 0%-5%/liter, respectively. There was no absorption of labeled T4 in the patient with a duodenum only. No consistent relationship was found between absorption and bowel length distal to the duodenum.     

Amitriptyline absorption in a patient with short bowel syndrome

Oral drug therapy in patients with short bowel syndrome can be quite challenging. We report the case of a 40-yr-old woman with short bowel syndrome and depression requiring antidepressant drug therapy. After buccal administration of amitriptyline, therapeutic serum antidepressant concentrations were attained despite the patient having only 18 inches of proximal small bowel. Clinical improvement in mood was seen, with the only drug side effects being dry mouth and bitter drug taste. Buccal absorption likely is playing a major role in attaining therapeutic serum tricyclic antidepressants drug concentrations.     

Conjugated bile acid replacement therapy in short bowel syndrome patients with a residual colon

AIM: To test the efficacy of cholylsarcosine (synthetic conjugated bile acid) and ox bile extracts (mixture of natural conjugated bile acids) on fat absorption, diarrhea, and nutritional state in four short bowel syndrome (SBS) patients with a residual colon not requiring parenteral alimentation. METHODS: The effect of cholylsarcosine (2 g/meal) on steatorrhea and diarrhea was examined in short-term balance studies with a constant fat intake in all four patients. The effect of continuous cholylsarcosine ingestion on nutritional state was assessed by changes in body weight in three patients. In two patients, the effects of cholylsarcosine were compared with those of ox bile extracts. Because of the low incidence rate of SBS this is not a controlled study. RESULTS: In balance studies, cholylsarcosine increased fat absorption from 65.5 to 94.5 g/day (a 44 % increment), an energy gain of 261 kcal/d. Fecal weight increased by 26 %. In two patients natural conjugated bile acids also reduced steatorrhea, but greatly increased diarrhea. As outpatients consuming an unrestricted diet and ingesting cholylsarcosine, three patients gained weight at an average rate of 0.9 kg/week without worsening of diarrheal symptoms. CONCLUSIONS: Cholylsarcosine is efficacious and safe for enhancing fat absorption and nutritional status in short bowel syndrome patients with residual colon. Natural conjugated bile acids improve steatorrhea to a smaller extent and greatly worsen diarrhea.     

Intestinal adaptation in patients with short bowel syndrome

Functional adaptation of remaining intestine was evaluated in 30 patients with extensive small bowel resection. Calcium and xylose absorption tests were compared. Calcium absorption was measured by a double-radiotracer technique. Serum xylosemia was measured 2 hr after D-xylose ingestion. Patients were divided into two groups according to the time interval between surgery and evaluation: less (group I) or more (group II) than two years. A statistically significant correlation was found between xylosemia and remaining small bowel length (r = 0.71; P less than 0.001) and between calcium absorption and remaining small bowel length (r = 0.75; P less than 0.001) in group I. A significant correlation was also observed between calcium absorption and time after surgery (r = 0.65; P = 0.001) but not for xylose absorption. Calcium absorption value was significantly increased in group II patients compared with group I patients matched for remaining small bowel length (36.2 +/- 12.5% vs 14.5 +/- 9.1%; P less than 0.001) while no difference was observed between the two groups concerning xylose absorption. These data indicate that intestinal calcium absorption continues to increase for more than two years after a major bowel resection in man. The intestine does not seem to recover all its functions at the same time.     

Clinical management of patients with short bowel syndrome

Diarrhoea, malabsorption and malnutrition characterise the short bowel syndrome. The underlying gastrointestinal disorders, the types of intestinal resections performed and the subsequent pathophysiological situations are reviewed. Recommended therapeutic measures in the postoperative period as well as in the rehabilitation of patients with short bowel syndrome are discussed in more detail. In the postoperative period, parenteral nutrition is essential followed by an enteral diet to stimulate bowel adaptation, reduce fluid loss and increase nutrient absorption. The final diet should be based on the anatomy of the retained bowel (presence or absence of a colon and ileum). The importance of the colon as a digestive organ in patients with short bowel and the need of a low-oxalate diet are underlined. The possible benefit of new treatment options (glutamine, growth hormone and glucagon-like peptide 2) is discussed. Both typical complications of the short bowel syndrome and management of these complications are presented.     

Plasma levels and intestinal absorption of 25-hydroxyvitamin D in patients with small bowel resection.

Plasma levels of 25-hydroxyvitamin D (25-OHD) were found to be significantly reduced in a group of patients with small bowel resection when compared with normal controls. Plasma levels of 25-OHD after an oral dose of 25-hydroxyvitamin D3 (25-ohd3) were also reduced in the patient group. Dietary intake of vitamin D tended to be low in many patients, but seasonal variation of plasma 25-OHD levels indicated normal exposure to sunlight in most of the patients studied. It is suggested that these studies provide some evidence for malabsorption of 25-OHD after small bowel resection, which, it is postulated, may be due to interruption of the enterohepatic circulation of bile acids and of 25-OHD. These factors may contribute towards the low plasma levels of 25-OHD found in the patient group.     

Definitions of intestinal failure and the short bowel syndrome

The European Society for Clinical Nutrition and Metabolism defined intestinal failure (IF) as “the 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”. IF is classified as type 1-acute, type 2-prolonged acute and type 3-chronic IF. A short bowel syndrome (SBS) due to the intestinal malabsorption associated with a functional small intestine length of less than 200 cm is the most frequent mechanism of IF. SBS is a difficult and multifaced disease. Complications due to SBS itself and to treatments, such as long term home parenteral nutrition, can adversely affect the patient outcome. The care of SBS requires complex technologies and multidisciplinary and multiprofessional activity and expertise. Patient outcome is strongly dependent on care and support from an expert specialist team. This paper focuses on the aspects of the pathophysiology and on the complications of SBS, which are most relevant in the clinical practice, such as intestinal failure associated liver disease, renal failure, biliary and renal stones, dehydration and electrolyte depletion, magnesium deficiency and d-lactic acidosis.     

Surgical management and autologous intestinal reconstruction in short bowel syndrome

Short bowel syndrome (SBS) is a serious condition with considerable morbidity and mortality. When treatment with parenteral nutrition fails and life-threatening complications occur, autologous intestinal reconstruction (AIR) should be considered before intestinal transplantation (ITx). Single or combined ITx should be reserved for patients with severe liver disease and as last resort in the treatment of SBS. Longitudinal intestinal lengthening and tailoring (LILT) has proven its value in AIR, but its availability depends on the expertise of the surgeons. Serial transverse enteroplasty (STEP) has similar success rates as LILT and fewer patients progress to ITx. STEP is also applicable at small bowel dilatation in ultra-short bowel syndrome. The scope may be widened when duodenal dilatation can be treated as well. Spiral intestinal lengthening and tailoring (SILT) is a promising alternative. More research is needed to confirm these findings. Therefore we suggest an international data registry for all intestinal lengthening procedures.     

The management of patients with the short bowel syndrome

The surgeon is invariably the primary specialist involved in managing patients with short bowel syndrome. Because of this they will play an important role in co-ordinating the management of these patients. The principal aims at the initial surgery are to preserve life, then to preserve gut length, and maintain its continuity. In the immediate postoperative period, there needs to be a balance between keeping the patient alive through the use of TPN and antisecretory agents and promoting gut adaptation with the use of oral nutrition. If the gut fails to adapt during this period, then the patient may require therapy with more specific agents to promote gut adaptation such as growth factors and glutamine. If following this, the patient still has a short gut syndrome, then the principal options remain either long term TPN, or intestinal transplantation which remains a difficult and challenging procedure with a high mortality and morbidity due to rejection.     

Human gut hormone profiles in patients with short bowel syndrome

We have studied gut hormone profiles in a small number of patients on treatment with home parenteral nutrition following near-total enterectomy who had no evidence of Inflammatory bowel disease and who were otherwise healthy. These and age- and sex-matched controls had gut hormone profiles measured after an overnight fast and a standard test meal. Circulating pancreatic glucagon concentrations and profiles were the same in both groups as were the Neurotensin and VIP. Peptide YY (PYY) concentrations and profiles were markedly raised in the short bowel group. It is suggested that the normal glucagon responses reflect the integrity of the remaining duodenum and pancreas. Circulating neurotensin and VIP originate largely from outside the bowel and so the removal of the gut source does not significantly affect their profiles. Enteroglucagon and PYY are secreted from terminal ileum and colon in response to unabsorbed food residues. The elevated circulating levels and profiles are consistent with those observed by others in patients with jejunoileal bypass or major resections in whom unabsorbed nutrients reach the colon.     

Quantitation of fecal carbohydrate excretion in patients with short bowel syndrome

We performed inpatient balance studies in 11 patients to evaluate the role of carbohydrate malabsorption in the pathogenesis of the diarrhea seen in short bowel syndrome. Stool weight, total reducing substance as measured by Clinitest, and total fecal carbohydrate as measured by anthrone were determined. Patients had markedly increased fecal carbohydrate excretion, up to 65% of dietary carbohydrate intake. When the diet contained oligosaccharides, measures of total reducing substance greatly underestimated fecal carbohydrate excretion and were unreliable for quantitation. Stool weight correlated with total fecal carbohydrate excretion and with total reducing substance (r = 0.79, p less than 0.001). Multiple balance studies in 2 patients suggested a relationship between both the amount and type of dietary carbohydrate and fecal carbohydrate excretion. These studies suggest that carbohydrate malabsorption is a major cause of the watery diarrhea and subsequent fluid, electrolyte, and acid-base imbalance seen in patients with short bowel syndrome.     

Role of parenteral nutrition in patients with short bowel syndrome.

More patients with extensive resection of the small bowel--secondary to regional enteritis, mesenteric infarction, cancer, etc.--are surviving perioperative treatment. To avoid nutrition-caused malabsorption and to maintain body composition, intravenous nutrition is initiated with a silastic atrial catheter in the immediate postoperative period. The patients are trained in "home hyperalimentation" procedures designed to allow normal nutrition to be maintained during the months required for bowel adaptation to occur. Because bowel adaptation to the absorption and transport of foodstuffs is in part dependent on the intraluminal presence of foodstuffs, elemental and regular diets are ingested during the period of intravenous support which may last for years. By using combined oral and intravenous nutrition, approximately 20 per cent of patients with short bowel syndrome eventually can take sufficient oral nutrients to sustain life.     

Small intestinal bacterial overgrowth in patients with irritable bowel syndrome

BACKGROUND: Small intestinal bacterial overgrowth (SIBO) has been proposed to be common in irritable bowel syndrome (IBS), with altered small-bowel motility as a possible predisposing factor. AIM: To assess the prevalence of SIBO, by culture of small-bowel aspirate, and its correlation to symptoms and motility in IBS. METHODS: 162 patients with IBS who underwent small-bowel manometry and culture of jejunal aspirate were included. Cultures from 26 healthy subjects served as controls. Two definitions of altered flora were used: the standard definition of SIBO (>/=10(5) colonic bacteria/ml), and mildly increased counts of small-bowel bacteria (>/=95th centile in controls). RESULTS: SIBO (as per standard definition) was found in 4% of both patients and controls. Signs of enteric dysmotility were seen in 86% of patients with SIBO and in 39% of patients without SIBO (p = 0.02). Patients with SIBO had fewer phase III activities (activity fronts) than patients without SIBO (p = 0.08), but otherwise no differences in motility parameters were seen. Mildly increased bacterial counts (>/=5x10(3)/ml) were more common in patients with IBS than in controls (43% vs 12%; p = 0.002), but this was unrelated to small intestinal motility. No correlation between bacterial alterations and symptom pattern was observed. CONCLUSIONS: The data do not support an important role for SIBO according to commonly used clinical definitions, in IBS. However, mildly increased counts of small-bowel bacteria seem to be more common in IBS, and needs further investigation. Motility alterations could not reliably predict altered small-bowel bacterial flora.