Gastric secretion after massive small bowel resection

How to manage a high-output stoma

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.

Practical Guide to Intestinal Rehabilitation for Postresection Intestinal Failure: A Case Study

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.

Short Bowel Syndrome and Intestinal Failure in Crohn's Disease

Crohn's disease is a chronic and progressive inflammatory disorder of the gastrointestinal tract. Despite the availability of powerful immunosuppressants, many patients with Crohn's disease still require one or more intestinal resections throughout the course of their disease. Multiple resections and a progressive reduction in bowel length can lead to the development of short bowel syndrome, a form of intestinal failure that compromises fluid, electrolyte, and nutrient absorption. The pathophysiology of short bowel syndrome involves a reduction in intestinal surface area, alteration in the enteric hormonal feedback, dysmotility, and related comorbidities. Most patients will initially require parenteral nutrition as a primary or supplemental source of nutrition, although several patients may eventually wean off nutrition support depending on the residual gut anatomy and adherence to medical and nutritional interventions. Available surgical treatments focus on reducing motility, lengthening the native small bowel, or small bowel transplantation. Care of these complex patients with short bowel syndrome requires a multidisciplinary approach of physicians, dietitians, and nurses to provide optimal intestinal rehabilitation, nutritional support, and improvement in quality of life.

Pharmacologic management of diarrhea in patients with short bowel syndrome

Diarrhea associated with short bowel syndrome (SBS) can have multiple etiologies, including accelerated intestinal transit, gastric acid hypersecretion, intestinal bacterial overgrowth, and malabsorption of fats and bile salts. As a result, patients may need multiple medications to effectively control fecal output. The armamentarium of antidiarrheal drugs includes antimotility agents, antisecretory drugs, antibiotics and probiotics, bile acid-binding resins, and pancreatic enzymes. An antidiarrheal regimen must be individualized for each patient and should be developed using a methodical, stepwise approach. Treatment should be initiated with a single first-line medication at the low end of its dosing range. Dosage and/or dosing frequency can then be slowly escalated to achieve maximal effect while minimizing adverse events. If diarrhea remains poorly controlled, additional agents can be incorporated sequentially. If modification of the regimen is required, a single medication should be altered or exchanged at a time. After each adjustment of the regimen, sufficient time should be permitted to fully assess response (≥3-5 days) before initiating additional changes. SBS-associated malabsorption is a major obstacle to optimization of an antidiarrheal regimen because drug absorption is impaired. Patients may benefit from high dosages and/or frequent dosing intervals, liquid preparations, or nonoral routes of drug delivery. Although the diarrhea associated with SBS can be debilitating, effective pharmaceutical management has the potential to substantially improve health outcomes and quality of life for these patients.

Complications of enterocutaneous fistulas and their management

Complications related to enterocutaneous fistulas are common and include sepsis, malnutrition, and fluid or electrolyte abnormalities. Intestinal failure is one of the most feared complications of enterocutaneous fistula management and results in significant patient morbidity and mortality. The authors review emerging trends in the medical and surgical management of patients with intestinal failure.

Effect of an H2-receptor blocking agent on diarrhoeas after extensive small bowel resection in Crohn's disease

The effect of an H2-receptor blocking agent, cimetidine, on faecal losses of fluid, electrolytes and fat was examined in 10 patients with Crohn's disease, who had diarrhoeas after extensive small bowel resection. A randomized, double-blind and cross-over design was applied, and patients were hospitalized and on a defined diet during the study. Cimetidine, 4 x 400 mg, significantly reduced diarrhoeal volumes by an average of 22% (p less than 0.05) and faecal sodium by 27% (p less than 0.05). Patients with severe diarrhoeas responded better to treatment. No side-effects were recorded. The reported data suggest that cimetidine may be useful in symptomatic treatment of patients with severe diarrhoeas after extensive ileal resection. Due to deficient drug absorption, higher doses may be needed for optimal effect.

Role of the colon in short bowel syndrome and intestinal transplantation

Colon is a crucial partner for small intestinal adaptation and function in patients who underwent extensive small intestinal resection or transplantation. This short review deals with the different properties and roles of the colon in these settings, involving fluid and electrolytes absorption, absorption of medium-chain triglycerides, and production of short-chain fatty acids for malabsorbed energy salvage. The colon may adapt after small intestinal resection, whereas it hosts the most important part of the intestinal microbiota, which plays a crucial role in intestinal function and health. Also, colon may be responsible for D-lactic acidosis as well, as it can be injured by noninfectious colitis. Finally, the relevance of a simultaneous colon grafting is discussed as it is occasionally considered in specific patients requiring intestinal transplantation.

Short bowel syndrome: current medical and surgical trends

Short bowel syndrome is a chronic malabsorptive state usually resulting from extensive small bowel resections. A combination of diarrhea, nutrient malabsorption, dysmotility, and bowel dilatation may constitute the clinical symptomatology of this syndrome. The remaining bowel undergoes a process called adaptation, which may replace lost intestinal function. Chronic complications include nutrient, electrolyte, and vitamin deficiencies. Therapy depends largely on the administration of various factors stimulating intestinal adaptation of the remaining bowel. If the patient despite medical therapy fails to return to oral diet alone, then long-term parenteral nutrition is required. However, long-term parenteral nutrition may gradually induce cholestatic liver disease. Surgical methods may be required for treatment including intestinal transplantation, as a last resort for the treatment of end-stage intestinal failure. The goal of this review is to analyze the clinical spectrum and pathophysiologic aspects of the syndrome, the process of intestinal adaptation, and to outline the medical and surgical methods currently used to treat this complicated group of patients.

Management of patients with a short bowel

There are two common types of adult patient with a short bowel, those with jejunum in continuity with a functioning colon and those with a jejunostomy. Both groups have potential problems of undernutrition, but this is a greater problem in those without a colon, as they do not derive energy from anaerobic bacterial fermentation of carbohydrate to short chain fatty acids in the colon. Patients with a jejunostomy have major problems of dehydration, sodium and magnesium depletion all due to a large volume of stomal output. Both types of patient have lost at least 60 cm of terminal ileum and so will become deficient of vitamin B₁₂. Both groups have a high prevalence of gallstones (45%) resulting from periods of biliary stasis. Patients with a retained colon have a 25% chance of developing calcium oxalate renal stones and they may have problems with D (-) lactic acidosis. The survival of patients with a short bowel, even if they need long-term parenteral nutrition, is good.

Management of patients with a short bowel

Short bowel syndrome most commonly results after bowel resections for Crohn's disease. The normal human small intestinal length ranges from about 3 to 8 m, thus if the initial small intestinal length is short, a relatively small resection of the intestine may result in the problems of a short bowel. Two types of patient with a short bowel are encountered in clinical practice: those with their jejunum anastomosed to a functioning colon, and those with a jejunostomy. Both types of patient have problems absorbing adequate macronutrients, and both need long-term vitamin B12 therapy. Patients with a jejunostomy also have major problems with large stomal losses of water, sodium, and magnesium. This high-volume jejunostomy output is treated by restricting oral fluids, giving a glucose-saline solution to drink, and using drugs that either reduce gastrointestinal motility (loperamide or codeine phosphate) or secretions (H2 antagonists, proton pump inhibitors, or octreotide). Patients whose jejunal length is less than 100 cm, and whose stomal output is greater than their oral intake, benefit most from antisecretory drugs. In patients with a retained colon, bacterial fermentation of unabsorbed carbohydrate in the colon results in energy being salvaged. However, they have increased oxalate absorption and a 25% chance of developing calcium oxalate renal stones. Thus patients with a colon are advised to eat a high-energy diet rich in carbohydrate but low in oxalate. Patients with a jejunostomy need a high-energy iso-osmolar diet with added salt. Both patient types have a 45% prevalence of gallstones. With current therapy most patients with a short bowel have a normal body mass index and a good quality of life.

Effect of restorative proctocolectomy on gastric acid secretion and serum gastrin levels: a prospective study

PURPOSE

The aim of the present study was to analyze gastric acid secretion after restorative proctocolectomy, because it has been shown that ileal resection or exclusion may increase gastric acid secretion. An increased output of gastric acids may decrease the intestinal passage time and contribute to looser stools.

METHODS

Eleven patients who had elective colectomy and ileoanal pouch because of ulcerative colitis were investigated. Eight patient were males. Eight S-pouches and three J-pouches were constructed. Gastric acid secretion (retention, basic, and stimulated) was studied, together with serum gastrin, pentagastrin, and pepsinogen, in patients before colectomy and after having had the pelvic pouch functioning for 12 months.

RESULTS

A significant increase, compared with preoperative levels, in retention, basic, and stimulated gastric acid secretion was found after 12 months with the pouch functioning. Levels of serum gastrin, pentagastrin, and pepsinogen were unchanged.

CONCLUSION

Restorative proctocolectomy leads to a significant increase in gastric acid secretion. These findings may be of importance with regard to intestinal passage time and consistency of the stools.

Short bowel syndrome

This article discusses the causes, prognosis, and management of short bowel syndrome. Attempts to enhance intestinal adaptation with trophic factors and surgical treatment options, including small bowel transplantation, are discussed.

Effect of 50% small bowel resection on gastric prostaglandin E2 levels in rats

The mechanism for the production of increased gastric secretion following massive intestinal resection is not clearly defined. The loss of an intestinal inhibitor has been most frequently suggested to explain this hypersecretion. The role of endogenous prostaglandins which can inhibit gastric secretion is not established. The present study was undertaken to determine the effect of 50% proximal small bowel resection on Prostaglandin E2 (PGE2) levels in rat gastric mucosa. This study was performed in 30 rats divided into three groups. The first group of rats served as unoperated controls, the second group was sham operated and the third group underwent 50% resection of proximal small intestine. The PGE2 levels in rat gastric mucosa was decreased significantly (p < 0.001) in the resected group (422.85 +/- 7.66 pg/gm) as compared with the sham group (478.77 +/- 7.25 pg/gm) and the control group (493.38 +/- 4.61 pg/gm). Total gastric acidity was increased significantly (p < 0.001) in the resection group (63.05 +/- 2.64 mEq/L) as compared with the sham group (15.21 +/- 0.99 mEq/L) and the control group (17.19 +/- 0.80 mEq/L). The PGE2 levels and total gastric acidity were not significantly changed in either the control or sham operation groups (p > 0.05). The results suggest that endogenous prostaglandin synthesis has a regulatory role in gastric hyperacidity after 50% proximal small bowel resection in rats.

Gastrointestinal hormones in short bowel syndrome. Peptide YY may be the 'colonic brake' to gastric emptying

BACKGROUND

Short bowel patients with a jejunostomy have large volume stomal outputs, which may in part be due to rapid gastric emptying of liquid. Short bowel patients with a preserved colon do not have such a high stool output and gastric emptying of liquid is normal.

AIMS

To determine if differences in the gastric emptying rate between short bowel patients with and without a colon can be related to gastrointestinal hormone changes after a meal.

SUBJECTS

Seven short bowel patients with no remaining colon (jejunal length 30-160 cm) and six with jejunum in continuity with a colon (jejunal length 25-75 cm), and 12 normal subjects.

METHODS

The subjects all consumed a 640 kcal meal; blood samples were taken for 180 minutes for measurement of gastrointestinal hormones.

RESULTS

Patients with a colon had high fasting peptide YY values (median 71 pmol/l with a colon; 11 pmol/l normal subjects, p < 0.005) with a normal postprandial rise, but those without a colon had a low fasting (median 7 pmol/l, p = 0.076) and a reduced postprandial peptide YY response (p < 0.050). Motilin values were high in some patients without a colon. In both patient groups fasting and postprandial gastrin and cholecystokinin values were high while neurotensin values were low. There were no differences between patient groups and normal subjects in enteroglucagon, pancreatic polypeptide, or somatostatin values.

CONCLUSIONS

Low peptide YY values in short bowel patients without a colon may cause rapid gastric emptying of liquid. High values of peptide YY in short bowel patients with a retained colon may slow gastric emptying of liquid and contribute to the "colonic brake'.

Time course of adaptive regulatory peptide changes following massive small bowel resection in the dog

Basal and postprandial concentrations of gastrointestinal hormones were measured in 12 dogs before and at one and three months after a 75% small bowel resection. Five animals were studied again at six months. Concentrations of enteric hormones and neuropeptides, measured in the proximal jejunum and distal ileum adjacent to the anastomotic site at the time of euthanasia, were compared with concentrations in control tissues taken from each animal at the time of resection. Increased basal and postprandial levels of gastrin (P < 0.05), cholecystokinin (CCK, P < 0.05), glucose-dependent insulinotropic peptide (GIP, P < 0.01), peptide YY (PYY, P < 0.001), and enteroglucagon (P < 0.001), were seen at one month after small bowel resection. In contrast, no significant changes were seen in concentrations of secretin, motilin, neurotensin, somatostatin, PP, or glucagon. Concentrations of enteroglucagon, GIP, and PYY remained high throughout the six-month study period. In contrast, gastrin and CCK had normalized by three months. Thus, only enteroglucagon, PYY, and GIP showed sustained elevations following enterectomy; the gastrin and CCK changes were transient. Following enterectomy, concentrations of vasoactive intestinal polypeptide (VIP) were reduced by about 50% in mucosal (P < 0.001) and muscle (P < 0.05) layers of proximal and distal gut. In contrast, calcitonin gene-related peptide (CGRP) was increased by about twofold in jejunal and ileal mucosa (P < 0.05), and CGRP elevations were even more marked in the muscle layers (P < 0.001). Somatostatin and neuropeptide Y (NPY) concentrations were similar to controls in all areas except for a small decrease in NPY in ileal mucosa (P < 0.05). These findings suggest that the increased motilin and PP concentrations previously reported after bowel resection in man are more likely to reflect underlying inflammatory bowel disease rather than enterectomy. The normalization of hypergastrinemia explains why the increased acid secretion after small bowel resection is transient. These results provide evidence for independent secretory control of enteroglucagon and PYY, which are both products of intestinal L cells. In addition, these studies reveal marked changes in enteric neuropeptide concentrations following bowel resection. VIP, which is thought to be a major inhibitory transmitter in the gut, is markedly reduced, while CGRP, which is mainly localized in sensory afferent fibers, is increased. These major neuropeptide changes are likely to be of importance in the adaptive responses to massive small bowel resection.

Postresection hypergastrinemia correlates with malabsorption but not adaptation

Massive intestinal resection is associated with transient hypergastrinemia and gastric hypersecretion. Gastric hypersecretion impairs intestinal absorption, but gastrin may be trophic during intestinal adaptation. Our aim was to determine if postresection hypergastrinemia correlates with malabsorption or adaptation. Ten dogs (13 to 19 kg) underwent 75% proximal intestinal resection. Intestinal remnant length and villus height was assessed at 12 weeks (n = 5) and 40 weeks (n = 5). Body weight and serum albumin, as well as stool fat, moisture, and weight, were measured preoperatively and at 4-week intervals for 40 weeks. Fasting serum gastrin values were measured by radioimmunoassay at similar intervals. Significant hypergastrinemia occurred between 4 and 28 weeks postresection. Hypergastrinemia did not correlate with increased intestinal remnant length (r = -.486, p = .407) or villus height (r = -.410, p = .584). Duration of hypergastrinemia (> 100 pg/ml) correlated with percentage of fecal fat at 12 weeks (r = .807, p = .015) and stool weight at 40 weeks (r = .881, p = .046). Thus, postresection hypergastrinemia correlates with early fat malabsorption and increased stool weight, but there is no correlation between hypergastrinemia and adaptation. These findings suggest that gastric hypersecretion, not hypergastrinemia, may be the more important pathophysiologic event after intestinal resection.

Management of the short bowel syndrome in the pediatric population

The short bowel syndrome in the pediatric population most commonly results from neonatal necrotizing enterocolitis. Multiple remedial surgical procedures have been developed to manage the rapid intestinal transit, decreased mucosal surface area, ineffective peristalsis, and short intestinal length in these patients. Despite significant morbidity, the overall outcome is favorable and warrants aggressive nutritional support, medical management, and surgical intervention in selected patients.

Changes in gastric mucosal histamine and prostaglandin E2-like activities in relation to portal somatostatin following small bowel resection in guinea-pigs

The effects of 85% intestinal resection on the portal somatostatin (SLI) gastric mucosal histamine (HA) and prostaglandin E2 (PGE2)-like activities were studied in guinea-pigs. A considerable increase in gastric mucosal HA-like activity of guinea-pigs subjected to small bowel resection (189.9 +/- 15.0 ng/g tissue) was measured in comparison to control values (42.9 +/- 6.3 ng/g tissue) (p < 0.001). The mean tissue PGE2-like activity in the sham operated group was 1636.9 +/- 128.8 ng/g tissue, whereas in the test group it was 650.5 +/- 59.3 ng/g tissue. After 85% small bowel resection a significant fall in portal and systemic venous SLI values was observed (T = 0, p < 0.05). Thus, the small bowel seems to be a major source of the increase of gastric mucosal HA-like activity and the decrease in PGE2-like activity.

Reoperation in patients with the short bowel syndrome

The clinical courses of 53 adult patients with the short bowel syndrome (SBS) were evaluated to determine the incidence of and indications for reoperation. Mesenteric vascular disease (23 patients) and malignancy/irradiation (18 patients) were the most frequent causes of resection. Early reoperation was necessary in nine (17%) patients, primarily for intestinal complications. Twenty (53%) of the 38 patients leaving the hospital required a later abdominal procedure during the mean follow-up of 30 months (range: 2 to 108 months). Three (33%) of nine patients with ulcer disease had gastric resection. Six (21%) of 28 patients at risk for cholelithiasis developed symptoms. Four of these patients underwent cholecystectomy, and three others had a prophylactic cholecystectomy. Ten patients underwent ostomy closure or formation. Intestinal disease necessitated stricturoplasty (three), serosal patch (one), minimal resection (three), or takedown of an ileal conduit (one). Twenty-four (63%) of 38 patients with SBS received home total parenteral nutrition for a mean of 22 months (range: 2 to 105 months). Eleven patients required more than 1 vascular access procedure, and 4 had more than 3 procedures. Patients with the SBS frequently require reoperation for intestinal conditions, cholelithiasis, peptic ulceration, and vascular access. Prophylactic cholecystectomy and strategies for preserving intestinal length are important considerations in these patients.

Effect of massive small bowel resection on gastric acid secretion in the rat

The phenomenon of a transitory gastric acid hypersecretory state after extensive bowel resection is well established. Its time of onset, however, is unknown. The purpose of this study was to determine the immediate effect of massive small bowel resection (MSBR) on gastric acid secretion (GAS). An anesthetized innervated rat model was prepared with gastric and jugular cannulae. Three groups of animals were studied: group I (n = 12), basal unstimulated state; group II (n = 12), pentagastrin (Pg) 16 micrograms/kg h-1 stimulated; and group III (n = 16), 5% liver extract meal (LEM) stimulated. Each group consisted of experimental animals that underwent 95% MSBR from proximal jejunum to terminal ileum and control animals that remained intact. Acid output was determined by extragastric titration with 0.1 M NaOH. Blood was taken for basal and postprandial serum gastrin levels. Basal acid output (mueq/10 min) significantly increased immediately after MSBR in all groups (p less than .01). Ninety minutes following MSBR, acid outputs were significantly elevated in basal and Pg-stimulated but not LEM-stimulated rats. Serum gastrin increased from 30 +/- 1 to 56 +/- 6 pg/mL (p less than .01) in group I rats and from 81 +/- 28 to 129 +/- 13 pg/mL in group III rats (p = NS). We conclude that GAS increases immediately after MSBR in group I and II rats. This increase in GAS may be mediated by gastrin release.

Severe posthemicolectomy diarrhea: evaluation and treatment with SMS 201-995

The effect of subcutaneous somatostatin analogue SMS 201-995 (Sandoz Pharmaceuticals Corp., East Hanover, NJ) was investigated in a patient with acute postoperative secretory diarrhea. The patient was hospitalized with bowel obstruction caused by a descending colon adenocarcinoma. One week after left hemicolectomy and transverse colostomy, watery colostomy output, which exceeded 10 L per day developed. Jejunal perfusion studies suggested that the patient's diarrhea was caused by abnormal net secretion of water and electrolytes by the small intestine. Circulating levels of various peptide hormones were normal with the exception of elevated level of pancreatic polypeptide. SMS 201-995 administration reduced colostomy output and normalized many of the abnormalities found during jejunal perfusion. These results indicate that the patient's acute secretory diarrhea, occurring after large intestinal obstruction, originated in the small intestine and that SMS 201-995 can be used to manage this unusual severe postoperative problem.

Clinical management of short-bowel syndrome. Enhancing the patient's quality of life

Management of patients following extensive small-bowel resection is complex. Parenteral nutrition is necessary initially because of a greatly reduced absorptive capacity. Intestinal adaptation occurs gradually and is stimulated by enteral feeding. Evaluation of specific nutrient status is essential, and supplementation may be required. The degree and consequences of malabsorption are more dependent on the anatomic location of resection than on the extent, but the outcome and eventual capacity for absorption in any given patient cannot be absolutely predicted. Even patients who do not achieve independence from parenteral nutrition receive many psychological and physiologic advantages by attaining the ability to consume some foods. Certain patients may subsist well on parenteral nutrition every other day without intravenous lipid. Such a regimen considerably reduces expense and simplifies clinical management, improving the quality of life.

Severe short bowel syndrome with a surgically reversed small bowel segment

We report a case of short bowel syndrome (60 cm of jejunum anastomosed to the left colon) with reversal of the distal 15 cm of jejunum in a 21-year-old man. The nutritional absorptive capacity and digestive motility was studied for 18 months postoperatively. His absorptive capacity reached subnormal values allowing him oral nutritive autonomy and normal social life. The results of the manometric study suggested that the reversed segment delayed intestinal transit time. The prolonged contact of the chyme with the intestinal absorptive mucosa possibly increased its absorptive capacity. Our data and the literature reports suggest that reversal of a bowel loop could help wean patients from their dependence on parenteral nutrition.

Gallstone disease in patients with severe short bowel syndrome dependent on parenteral nutrition

An increased incidence of gallbladder disease is seen in patients receiving long-term parenteral nutrition (PN). Stasis is thought to play a key role in the development of gallbladder sludge and gallstone formation. The highest incidence of gallbladder disease, by previous reports, is seen in patients with terminal ileal disease or resection. Since PN-dependent patients with severe short bowel syndrome secondary to mesenteric vascular accident have both gallbladder stasis and massive small bowel resection, a retrospective study was undertaken to evaluate the incidence of symptomatic gallbladder disease in this group. Of 11 patients followed over 9 years, five met the inclusion criteria of less than 60 cm of bowel remaining, receiving PN for longer than 6 months and the initial presence of a gallbladder. All five patients developed symptomatic gallbladder disease manifested by cholecystitis or pancreatitis. Factors contributing to gallbladder stasis included poor oral intake and use of anticholinergic and analgesic drugs. Gastric hypersecretion indirectly contributed to decreased oral intake as a means to minimize stool output. As these patients often require several laparotomies during the initial hospitalization, consideration should be given to performing prophylactic cholecystectomy, especially when the potential mortality and morbidity of emergent cholecystectomy done for symptomatic gallbladder disease is taken into account.

Alterations in serum gastrin levels and antral G- and D-cell population following extensive proximal small bowel resection (radioimmunoassay and immunocytochemical study in dogs)

Twelve dogs underwent an extensive proximal small bowel resection. Basal and postprandial serum gastrin levels increased significantly one and two months after the resection compared to the respective preoperative levels. The increase in serum gastrin levels two months after the resection was less prominent than the respective increase one month postoperatively. Antral G- and D-cell populations increased significantly two months after the resection compared to the respective populations before the resection. It is concluded that hypergastrinaemia following small bowel resection is due to the quantitative elimination of the inhibiting hormonal factors of gastric secretion and gastrin release. The adaptive increase of antral D-cell population could explain the temporary character of hypergastrinaemia.

Effects of cimetidine on jejunostomy effluents in patients with severe short-bowel syndrome

The effect of the H2-receptor blocking agent cimetidine on jejunal effluent was examined in eight short-bowel patients with high-output jejunostomies. Stool mass and faecal excretion of sodium and potassium were significantly reduced by intravenous injection of 400 mg cimetidine four times a day. The amount of calcium, magnesium, phosphate, zinc, and fat in jejunostomy effluent did not change significantly. Cimetidine may be considered an antidiarrhoeal drug in extensively small-bowel-resected patients with a jejunostomy and may reduce the need for parenteral saline supply in these patients.

Inhibition of pentagastrin-stimulated gastric acid secretion by intraileal administration of bile and elevation of plasma concentrations of gut glucagon-like immunoreactivity in anesthetized dogs

The effects of intraileal administration of bile on gastric acid secretion stimulated by a submaximal dose of intravenous pentagastrin infusion and on plasma concentrations of gut glucagon-like immunoreactivity (gut GLI) were studied in anesthetized dogs. Gastric acid secretion was measured for a 2-h period at 15-min intervals before and after intraluminal instillation of test solutions. 100 ml of canine bladder bile diluted to 10% in saline evoked a significant inhibition (20%) of gastric acid secretion. The inhibition of gastric acid secretion was accompanied by an elevation of plasma concentration of gut GLI, whereas saline instillation (in controls) caused no responses. Although the inhibition of gastric acid secretion and the elevation of plasma gut GLI are parallel phenomena, gut GLI can be reasonably postulated as one of the candidate mediators of bile-induced inhibition of gastric acid secretion, since its structurally related peptides, pancreatic glucagon, glicentin and oxyntomodulin have been reported as inhibitors of gastric acid secretion.

Gastric acid secretion and gastrin production in the short bowel syndrome

Excess gastric acid secretion and gastrin production may occur in patients with the short bowel syndrome but the two measurements have never been made simultaneously in man in response to a food stimulus. Using the technique of intragastric titration, this was carried out in eight patients after extensive small bowel resection resulting mainly from vascular occlusion and in eight matched normal control subjects. Basal acid output and peak acid output in response to pentagastrin was also measured separately. Although peak and integrated serum gastrin concentrations were significantly greater in patients (450 +/- SE 109 pg/ml; 113 +/- 2.9X10(-3) pg/ml/min) compared with control subjects (174 +/- 98 pg/ml; 6.1 +/- 2.0X10(-3) pg/ml/min p less than 0.05), no concomitant increase in acid secretion was shown either during intragastric titration or in response to pentagastrin. These findings indicate that there is no rationale for treating these patients with long term anti-ulcer therapy.

Surgical therapy for the short bowel syndrome

The introduction of total parenteral nutrition has resulted in more patients surviving massive intestinal resection. Long-term parenteral nutrition is expensive, has potential complications, and causes inconvenience for the patient. Therefore, interest persists in surgical therapy for the short bowel syndrome. The goals of surgical therapy in the short bowel syndrome are to slow intestinal transit, increase the area of absorption, and reduce gastric hyperacidity. Patients with sufficient absorptive area, but rapid intestinal transit, benefit from antiperistaltic segments or colon interposition. Intestinal valves yield inconsistent results. Recirculating loops are associated with prohibitive morbidity and mortality. Experience with intestinal pacing is limited. Patients with dilated bowel segments may benefit from intestinal tapering or lengthening. Growing neomucosa holds promise but has not been evaluated clinically. Recent improvement in the results of intestinal transplantation in animals may warrant clinical trials. The efficacy of H2 receptor antagonists makes procedures for reducing gastric hyperacidity less necessary. None of the operations to treat the short bowel syndrome are sufficiently safe and effective to recommend their routine use. Operations should be performed only on selected patients to achieve specific goals. Although investigation continues, our emphasis should continue to be conservation of as much of the intestine as possible when massive resection is necessary.

Gut hormone release after intestinal resection

To investigate the possible role of gut and pancreatic hormones in the adaptive responses to gut resection, plasma concentrations of the circulating hormones were measured, in response to a test breakfast, in patients with either small or large intestinal resection and in healthy control subjects. In 18 patients with partial ileal resection a significant threefold rise was found in basal and postprandial levels of pancreatic polypeptide, a fourfold increase in motilin, and more than a twofold increase in gastrin and enteroglucagon levels compared with healthy controls. In contrast, nine patients with colonic resection had a threefold rise in levels of pancreatic polypeptide only. One or more of these peptides may have a role in stimulating the adaptive changes found after gut resection.

Parietal cell volume, hypergastrinemia, and gastric acid hypersecretion after small bowel resection. Experimental study

One hundred and fifty male Sprague-Dawley rats were divided into six groups: control, antrectomy, truncal vagotomy with pyloroplasty, intestinal resection, antrectomy with intestinal resection, and truncal vagotomy with pyloroplasty and intestinal resection. In the control group gastric acid secretion and plasma levels of gastrin were calculated. In the other five groups the same calculations were made 3 months after the corresponding operations. In all animals samples of the gastric wall were taken after specific dyeing of the parietal cells of these samples. In all samples prepared in this way, the variables of parietal cell volume per unit of muscularis mucosa were obtained by a morphometric method. The statistical survey using the levels of gastric acidity, gastrinemia, and parietal volumes of the six groups of animals showed that there is no relation between gastrinemia and gastric acid secretion, nor between gastrinemia and parietal volume, but that there is a significant correlation between gastric acid secretion and parietal volume. Those results suggest that the parietal cell volume in the rat decreases when the secreting capacity of the mucosa is decreased, and that the plasma levels of gastrin do not have a direct trophic effect on the parietal cells of gastric mucosa.

Gastric and pancreatic hyposecretion following massive small-bowel resection

It is well established that massive small-bowel resection (MSBR) invariably causes hypersecretion of acid in animals with denervated gastric pouches. The effect of MSBR on the secretory responses of both the totally innervated stomach and pancreas have been less well studied. Eighteen adult mongrel dogs were prepared with chronic gastric and pancreatic fistulae. In eight, massive small-bowel resection was performed in addition. Bowel resection did not alter the responses to graded doses of pentagastrin. However, in response to the intragastric titration of a liver extract meal, it had the following effects: (1) profound gastric acid hyposecretion; (2) reduction in pancreatic bicarbonate and protein secretion; and (3) increase in basal and meal-stimulated serum glucagon levels. Hypergastrinemia did not occur after resection. The hyposecretory responses may represent either increased inhibition or decreased secretory stimulation.

Effect of 50 percent distal small bowel bypass on gastric secretory function in rhesus monkeys

Six rhesus monkeys had basal acid output and histamine-stimulated maximal acid output measured before and at 10 weeks and 6 months after 50 percent distal small bowel bypass. At each stage fasting serum gastrin was measured in all animals and fasting serum gastric inhibitory polypeptide in two animals. No change in basal or maximal acid output occurred after a sham operation carried out in two of the animals. The mean preoperative basal acid output (0.17 +/- 0.02) increased to 0.49 +/- 0.04 at 10 weeks after bypass (p less than 0.001) and then decreased significantly to 0.33 +/- 0.03 mEq/kg/hour at 6 months (p less than 0.001). Preoperative maximal acid output (0.43 +/- 0.06) increased to 0.76 +/- 0.10 mEq/kg/hour at 10 weeks (p less than 0.001) and remained at that level at 6 months. Small bowel biopsy specimens at 6 months showed characteristic changes in both proximal and distal small bowel segments. Fasting gastrin and gastric inhibitory polypeptide levels did not change significantly during the study. A comparison of these results with those obtained after 50 percent distal small bowel resection in a previous study revealed a similar proportional increase in maximal acid output in both early (resection, 78 +/- 20 percent; bypass, 77 +/- 23 percent) and late postoperative studies (resection, 57 +/- 14 percent; bypass, 74 +/- 19 percent). However, the early increase in basal acid output after resection (370 +/- 50 percent) was sustained and was significantly greater (p less than 0.005) than the early ill-sustained increase (188 +/- 24 percent) after bypass.

Nutritional aspects of malabsorption. Short gut adaptation

Adaptation of remaining small bowel after extensive intestinal resection plays an important part in maintaining adequate nutrition. The metabolic consequences of short bowel depend upon the anatomic extent of bowel removed, the functional condition of remaining digestive organs and the degree to which adaptive changes occur. The pathophysiology of short bowel results primarily from the abnormal absorption of nutrients and selective metabolites leading to malnutrition and other organ complications. Nutrients in the lumen of the small intestine are required to stimulate the process of intestinal adaptation (mucosal hyperplasia). This stimulation may be mediated via direct mucosal absorption or metabolism of nutrients, the presence of pancreaticobiliary secretions in the intestine, trophic effects of circulating enteric hormones, or neurovascular influences. Understanding the mechanisms by which mucosal growth may be stimulated could lead to important clinical applications.

Hyperacidity and hypergastrinemia following extensive intestinal resection

Increased gastric acid secretion occurs after extensive intestinal resection in man, dog, rat, and monkey. Hypergastrinemia has been observed in patients with short gut syndrome and appears to accompany the hyperacidity after intestinal resection in dog, rat, and monkey. Postresectional hypergastrinemia is caused by increased release of gastrin and/or decreased degradation of the hormone. Other hormonal changes after extensive resection include increased insulin, GIP, pancreatic glucagon, and decreased enteroglucagon.

Effect of proximal gastric vagotomy and truncal vagotomy and pyloroplasty on gastric functions and growth in puppies after massive small bowel resection

The effects of truncal vagotomy and pyloroplasty and proximal gastric vagotomy on gastric acid hypersecretion, hypergastrinemia, and growth after massive bowel resection were studied in beagle puppies. In puppies with 80% enterectomy, neither type of vagotomy alters significantly the postprandial hypersecretion of acid from the Heidenhain pouch or the concentration of serum gastrin. Proximal gastric vagotomy tended to decrease the hypersecretion more than did truncal vagotomy. In beagle puppies undergoing 70% small bowel resection, growth was significantly decreased but survival was not impaired. Neither proximal gastric vagotomy nor truncal vagotomy and pyloroplasty reversed completely the impaired growth produced by massive resection. Proximal gastric vagotomy caused a small improvements in growth, while truncal vagotomy and pyloroplasty resulted in a slight decrease in growth. It remains possible that proximal gastric vagotomy could be of value in the management of growing infants with hypersecretion of acid due to short bowel syndrome.

Inhibition of external pancreatic secretion by intracolonic and intraileal infusions in the cat

1. Infusions of oleic acid into the colon or the distal part of the ileum in anaesthetized cats inhibits secretion of water and amylase by the pancreas, stimulated by secretin and pancreozymin. Intraileal infusions of other non-water-soluble substances or hypertonic solutions can also inhibit the pancreas. 2. As inhibition can be produced after extrinsic denervation of the pancreas and gut, it must in part be humorally mediated. 3. Pentagastrin-stimulated gastric secretion of acid and pepsin is also inhibited by the intraileal infusions, but the inhibition of acid secretion is less than that of pancreatic secretion. 4. It is suggested that the physiological counterpart of the inhibitory effects induced by the infusion of non-physiological solutions into the colon or ileum is an inhibition of pancreatic secretion brought about by the cessation of intestinal absorption, which marks the completion of the post-prandial digestive process.