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Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

100 g of spinach a day was added to the hospital diet of fifty-four patients with suspected malabsorption. Hyperoxaluria was found in thirty-eight patients; all of them had steatorrhoea. No patient with steatorrhoea had a urinary oxalate excretion of less than 40 mg a day. Ten other patients had hyperoxaluria, but the faecal fat determinations were regarded as unreliable in almost all and malabsorption could not be confirmed. It is suggested that in clinical practice determination of urinary oxalate after an oral load of oxalate could replace faecal fat determination in most patients with suspected malabsorption.
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PMID:Urinary oxalate on a high-oxalate diet as a clinical test of malabsorption. 7 94

To investigate the possibility of measuring urinary oxalate output instead of faecal fat excretion as an outpatient screening test for steatorrhoea, we determined 24 hour urinary oxalate and five day faecal fat excretion before and during an oral load of sodium oxalate 600 mg daily (oxalate 4.44 mmol), in 32 patients with suspected malabsorption on a diet containing oxalate 30 mg (0.33 mmol), fat 50 g (180 mmol), and calcium 1 g (25 mmol). Nineteen patients proved to have steatorrhoea (mean faecal fat 62 mmol/24 h, range 19--186 mmol) of varying aetiologies. On the diet alone, urinary oxalate was raised in only nine of these patients (mean 0.25 mmol/24 h, range 0.08--0.59 mmol) (normal less than 0.20). By contrast, when the diet was supplemented with oral sodium oxalate, all 19 patients with steatorrhoea had hyperoxaluria (mean 0.91 mmol/24 h, range 0.46--1.44 mmol) (normal less than 0.44). There was a significant positive linear relationship between urinary oxalate and faecal fat when the 32 patients were on the high oxalate intake (r = 0.73, P less than 0.001), but not when they were on the low oxalate intake. Mean percentage absorption of orally administered oxalate was 5.8 +/- 0.99% (+/- 1 SD) in normal subjects and 14.7 +/- 6.0% (P less than 0.002) in patients with steatorrhoea. Measurement of urinary oxalate output during oral sodium oxalate loading appears to be a reliable and convenient screening test for steatorrhoea.
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PMID:Oxalate loading test: a screening test for steatorrhoea. 52 84

This work was designed to investigate the site of oxalate hyperabsorption in malabsorption syndromes. 1) Urinary oxalate excretion was measured in 27 patients with ileal resection (IR) and steatorrhea. Mean urinary oxalate excretion was high in 13 patients with IR and intact colon and in 9 subjects with IR and right hemicolectomy (90.2 +/- 11.9 and 108 +/- 18.6 mg per 24 hours; mean +/- S.E.M.), whereas it was normal in 5 patients with IR and ileostomy (21.9 +/- 4.4 mg per 24 hours). Steatorrhea was similar in the three groups. 2) On one patient of the last group in whom the colon had not been removed initially but excluded closure of the ileostomy resulted in the development of frank hyperoxaluria. 3) Intracolonic perfusion of calcium (1.93 g per day) abolished or greatly reduced the hyperoxaluria in 3 patients. These results indicate that the colon is the major site of oxalate hyperabsorption, and the right colon is not necessary for the development of hyperoxaluria in malabsorption syndromes.
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PMID:Evidence for excessive absorption of oxalate by the colon in enteric hyperoxaluria. 63 58

143 patients (70 patients with Crohn's disease, 11 with ulcerative colitis, 40 with an intestinal by-pass operation, 9 with non-tropical sprue, 10 with short bowel syndrome, and 3 with other gastrointestinal disease) were studied during a metabolic regime including a fixed oral supply of 70 g fat, 800 mg calcium, and 200 mg oxalate. Faecal fat, 47Ca-absorption, 14C-oxalate absorption, and renal oxalate excretion were measured, and in the majority of patients a 14C-glyco-cholic acid breath test was also performed. 14Ca-absorption was practically identical (r = 0.92), whether determined by whole-body counting or from the accumulation of absorbed 47Ca in the skeleton of the underarm. 14C-oxalate absorption and renal oxalate excretion agreed well (r = 0.85). Steatorrhoea correlated weakly with renal oxalate excretion (r = 0.63, p less than 0.001), whereas no correlation was present between faecal fat and calcium absorption or between oxalate and calcium absorption under the constant conditions prevailing during the study. It is recommended that a "trifixed" regime with absorption studies of fat, calcium, and oxalate be undertaken previous to therapy that aims at a reduction of steatorrhoea or hyperoxaluria or an improvement of calcium absorption in chronic malabsorption syndromes, not least because therapy of these categories of patients most often continues for years.
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PMID:Standardized ("trifixed") diet in the study of chronic malabsorption syndromes. 67 51

Oxalate-urolithiasis and hyperoxalaria have been reported to be a frequent complication in patients with small bowel disease, especially in patients with ileal resection due to Crohn's disease. Hyperabsorption of oxalate seems to be the main patholgenetic factor for "enteric" hyperoxalaria. Intestinal absorption and urinary excretion of oxalate was measured in patients with various gastrointestinal diseases after oral or rectal administration of 14C-oxalate. Kinetic data suggest that 14C-oxalate is absorbed in the small, the large bowel and the rectum as well. Oxalate absorption was decreased in patients with a colectomy and in active ulcerative colitis, but increased in patients with ileal resection, chronic liver disease, and steatorrhea due to chronic pancratitis or sprue. There existed a positive correlation between 14C-oxalate absorption and the amount of fecal fat excretion. The data suggest that hyperoxaluria and hyperabsorption of oxalate are not a specific finding in patients with bile acid malabsorption, but may occur too, in steatorrhea without alteration of bile acid metabolism.
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PMID:[Enteric hyperoxaluria. I. Intestinal oxalate absorption in gastrointestinal diseases (author's transl)]. 68 26

The effect of fat malabsorption on the absorption and renal excretion of dietary oxalate was studied in four patients with sprue and in two patients with dermatitis herpetiformis and sprue-like jejunal histology. Hyperoxaluria was present in all patients with sprue when fat malabsorption was severe. Urinary oxalate excretion decreased in two of the three patients with coeliac sprue when their fat malabsorption had improved after three months of dietary gluten restriction. Neither patient with dermatitis herpetiformis and sprue had steatorrhoea. In these patients, urinary oxalate excretion was always within normal limits. A significant positive linear relationship (y=28.25 +4-84x; r=0-82; P less than 0-01) was demonstrated between faecal fat and urinary oxalate excretion. The results of this study support the concept that severe malabsorption of dietary fat plays a primary causative role in enteric hyperoxaluria.
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PMID:Hyperoxaluria correlates with fat malabsorption in patients with sprue. 87 37

Urinary oxalate excretion was measured in healthy persons and patients with Crohn's disease, colitis ulcerosa, sprue and other diseases accompanied with malabsorption, and patients with insufficiency of the exocrine pancreas gland. Further measurements were made in patients after resection of parts of the small intestine or the colon. We found a clear increase of urinary oxalate excretion in patients with resected parts of the small intestine, sprue or other malabsorption syndromes. In 4 patients with resected parts of small intestine or pancreas we even found urolithiasis. Urinary oxalate excretion correlated significantly with steatorrhoea and increased if larger parts of small intestine were resected. Increased resorption of oxalate from food causes increased urinary excretion. Details about the patho-mechanism of this increased excretion are not known yet; an important factor seems to be the reduced absorption of fat in the small intestine.
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PMID:[Hyperoxaluriaas a complication of intestinal diseases (author's transl)]. 99 43

During the past several years there has been increasing interest in refunctionalizing patients who have undergone radical extirpative surgery for pelvic malignancies and patients with dysfunctional bladders. To accomplish this, intestinal segments have been successfully employed in a variety of configurations. Independent of their optimal urosurgical implementation these procedures are not without potential complications, a significant portion of which involve metabolic derangements. Besides first follow-up results of patients with bladder substitution or continent urinary diversion, analysis of experimental investigations and functionally comparable clinical conditions enables an insight into potential following physiopathological interrelationships. These concern, besides the problem of chronic metabolic acidosis, disorders of bile acid and vitamin B12 metabolism as well as the potential induction of a secondary hyperoxaluria with subsequent oxalate concrement diathesis. Furthermore, there may be a malabsorption of calcium and vitamin D with development of intestinal osteopathy due to the reduction of absorptive surface. Apart from these problems of enteral loss and deficiency manifestations, several case reports and investigations suggest that bone demineralization can occur as a consequence of chronic metabolic acidosis and patients are at risk of skeletal demineralization. The pathogenesis of this association has yet to be clarified. These physiopathological interrelationships must be considered in medical attendance of patients with intestinal substitute bladders and continent supravesical pouch systems over many years. As these procedures become more popular, it becomes important to identify any metabolic changes that may occur as their consequence.
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PMID:[Bladder replacement and continent diversion: what about metabolic complications?]. 184 45

Almost all segments of the gastrointestinal tract have been used as urinary tract substitutes. The specific nutritional and gastrointestinal complications depend on the particular portion of bowel that is removed from the alimentary tract. The use of stomach theoretically may predispose the patient to hypergastrinemia and peptic ulcer disease, hypocalcemia, and iron deficiency or megaloblastic anemia. Resection of a large amount of jejunum causes malabsorption. Limited use of colon segments usually is well tolerated, but loss of large parts of the colon directly decreases available absorptive area, resulting in diarrhea. Resection of the ileum and ileocecal valve can lead to several disease states. One is mixed secretory-osmotic diarrhea. Decreased ileal reabsorption of bile salts results in fat malabsorption and steatorrhea. The presentation of increased amounts of bile salts and fatty acids to the colon decreases water absorption and stimulates active chloride and water secretion, producing a cholera-like high-volume secretory diarrhea. The loss of the ileocecal valve and ileum segment accelerates intestinal transit time, which does not allow for complete digestion and absorption of food. Water and electrolytes remain associated with undigested food particles and may overwhelm the absorptive capacity of the colon, resulting in an osmotic diarrhea. A second problem is vitamin B12 deficiency. Surgical reduction of sites in the terminal ileum for active and exclusive uptake of vitamin B12 might lead to hypovitaminosis. If this is unrecognized, patients may develop irreversible neurologic injury. A third problem is cholelithiasis. Derangements in bile salt metabolism can occur when as little as 10 cm of ileum is resected, and the propensity to form gallstones is increased. Pigment gallstones appear to be the predominant stone associated with ileal resections. The fourth possible problem is urolithiasis, the etiology of which is multifactorial in patients with ileal resections. With decreased availability of bile salts, fat malabsorption occurs. Fatty acids bind with calcium and magnesium to form soaps, resulting in increased levels of free oxalate available for absorption. Moreover, fatty acids directly increase colonic permeability to oxalate.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Nutritional and gastrointestinal complications of the use of bowel segments in the lower urinary tract. 194 6

The active transport of conjugated bile acids by the ileum is responsible for the enterohepatic circulation of bile acids, a physiological process that ensures an ample supply to the intestine of these key biological surfactants, irrespective of the rate of their biosynthesis from cholesterol. The ileal bile acid transport system is a high capacity, low affinity secondary active Na+ co-transport system that differs in substrate specificity from that present in the hepatocyte. Ileal transport is homeostatically regulated by feedback inhibition of the bile acids that are transported. The enterohepatic circulation is responsible for the concentration profile present in the intestine--high concentrations in the small intestine and low concentrations in the large intestine. Loss of ileal absorption, when mild, leads to a sequence of events that result in increased concentrations in the large intestine causing diarrhea. Severe bile acid malabsorption causes decreased concentrations in the small intestine which in turn lead to fat maldigestion and fat malabsorption. The increased passage of fatty acids into the colon contributes to diarrhea. Fat maldigestion and malabsorption also causes increased absorption of dietary oxalate from the colon which causes hyperoxaluria and contributes to nephrolithiasis. In cholestatic liver disease, inappropriate upregulation of ileal bile acid transport is likely to cause retention of hepatotoxic endogenous bile acids. In familial hypercholesterolemia, efficient bile acid absorption contributes to downregulation of LDL receptors and the maintenance of elevated plasma cholesterol levels; upregulation of bile acid transport during bile acid sequestrant therapy could diminish its efficacy. Efforts are in progress to develop a suitable bile acid analogue to be administered orally for conditions of bile acid deficiency in the small intestine.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Biological and medical aspects of active ileal transport of bile acids. 206 93


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