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Query: UMLS:C0240066 (iron deficiency)
 7,156 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Young Aboriginal children in remote regions of tropical and desert Australia are at risk of developing urate stones in their upper urinary tract from an early age. These radiolucent calculi were only recognized with the availability of ultrasound diagnosis and are not associated with anatomic anomalies or abnormal uric acid production/metabolism. Although these stones appear to resolve spontaneously after the weaning period, some result in ureteric obstruction and infection which may lead to renal damage. This pattern of urolithiasis differs from the usual global urolithiasis pattern of either endemic bladder stones in young children in developing countries or predominantly calcium-based stones in upper tracts of older children and adults in affluent industrialized countries, where upper tract urate stones account for only a minority of childhood urinary tract stones. Risk factors for urate stones are low urine output and acidic urine. An association between urolithiasis and carbohydrate intolerance leading to chronic acidosis has been suggested for Aboriginal children, but existing limited evidence does not support this as a major aetiological factor. Although further studies on the epidemiology, natural history and management of these urate stones are needed, we believe the focus should be on improving the known social and environmental risk factors of remote Aboriginal children during the weaning period which contribute to the unacceptably high prevalence of failure to thrive, diarrhoeal disease, environmental enteropathy, iron deficiency and urolithiasis.
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PMID:Unique pattern of urinary tract calculi in Australian Aboriginal children. 1288 59