1、交通大学医学院附属交通大学医学院附属仁济医院消化科仁济医院消化科上海市消化疾病研究所上海市消化疾病研究所范范竹萍竹萍DiarrheaDefinitionincrease in the frequency of bowel movements increase in stool liquidityin some cases increase in daily stool weight (200g/d)Pathophysiological mechanismssecretory diarrhea (increased intestinal secretion)Osmotic diarrheaDec
2、reased intestinal surface area and/or intestinal absorptionInflammatary diarrheaRapid transit of intestinal contents (shortened transit time)Pathophysiological mechanismssecretory diarrhea (increased intestinal secretion)v infections (cholera toxin, E-col, salmonella, staphylococcal)v Hormonal (Gut
3、Hormones, ZES, VIP), cancer (calcitonin, Prostaglandins)v miscellaneous (laxatives abuse, villous adenoma of the rectum)agentsAdenylate cyclasecAMP systemsecretory diarrheaactivateNaCl secretory diarrhoeainfectioncholerahormonal Verner-Morrison syndrome (VIP associated) carcinoid syndrome gastrinoma
4、 medullary thyroid cancerphenolphthalein abuse bile salt malabsorptionCholera: the simplified versionVerner-Morrison syndrome (VIP associated)a profuse, watery diarrhoea that results in massive intestinal loss of water, potassium, sodium and bicarbonate, leading to hypovolaemia, hypokalaemia and red
5、uced total body potassium, and achlorhydria (metabolic acidosis).carcinoid syndromeparoxysmal flushing - for example, following coffee, alcohol, certain foods and drugs bronchoconstrictive episodes, similar to asthma right-sided heart failure episodes of explosive watery diarrhoea abdominal pain pel
6、lagra-like lesions of the skin and oral mucosagastrinoma The Zollinger-Ellison syndrome describes the association of:gastrin-producing tumours gastric hypersecretion severe peptic ulcer diseasegastrinomahigh fasting plasma gastrin high gastric acid secretion diminished response to pentagastrin demon
7、strable pancreatic or gastrointestinal tumour - by CT or venous sampling for gastrin more than 90% of gastrinomas have somatostatin receptors, and somatostatin receptor scintigraphy has been reported to be a especially sensitive method to image gastrinomasPathophysiological mechanismsOsmotic diarrhe
8、aIt caused by accumulation of the followings in the gut lumen watersalts poorly absorble solutes maldigestion of ingested food failure to transport an osmotically active dietary nonelectrolyte (E: glucose)intestinal Lumenbeing osmotically activediarrheaosmotic diarrhoeadisaccharidase deficiencyprima
9、rily lactase deficiencylaxative abuse(about 20% of patients Causes of diarrhea in enteral nutritionCalculation of osmotic gapPathophysiological mechanismsDecreased intestinal surface area and/or intestinal absorptionE: surgical removal; malabsorption syndromePathophysiological mechanismsRapid transi
10、t of intestinal contents (shortened transit time) E: irritable bowel syndrome Functional diarrhea laxatives abuse post vagotomy diarrhea post gastrectomy dumbing syndromestoolvolumeliquiditycontact time increasesmall bowel mucosa contentsincrease in intestinal motility (intestinal hurry)reduceEtiolo
11、gyAcute DiarrheainfectionFood poisoningSystematic diseases (influenza, sepsis, etc)MiscellanousEtiologyAcute Diarrheainfection1.viral 2. bacterialcampylobacteriaShigellaE. ColiSalmoneilaetc3.fungal4.parasitic (amebic Trophozoites, Giardia)Acute DiarrheaFood poisoningbacterial, plants, chemical poiso
12、n(arsenic,.)Systematic diseases (influenza, sepsis, measle, etc)MiscellanousAllergic diseases Allergic purpura, enteropathy.endocronic diseases (ZES, etc.)Drugs: laxatives, 5-Fu, etc.food poisoningbacterial intrinsically poisonous food, for example deadly nightshade, red kidney beans parasites in th
13、e meat, for example Taenia, Trichinella chemicalsheavy metals, e.g. mercury, zinc pesticides, e.g. rodenticides, insecticidesallergies paralytic shell fish poisoning scombrotoxin histamine intoxication viral food poisonining chinese restaurant syndrome - monosodium glutamatechinese restaurant syndro
14、meExcess ingestion of monosodium glutamate results in a syndrome that includes a burning sensation over the neck, chest and arms, with tightness over the face and chest. There may also be headache, flushing, weakness, nausea and abdominal cramps.EtiologyChronic DiarrheaIntestinalGastric(chronic gast
15、ritis,subtotal gastrectomy , etc.)Pancreatic (Chronic Pancreatitis, Pancreatic Cancer, etc.)Hepatobiliary(liver cirrhosis, obstructive jaundice)functional causesEndocronic (Hyperthyroids crisis, ZES, Carcinoids) Drugs (Reserpin, Ismelin, Laxatives, etc.)Others (uremia, hypogammaglobulemia, etc.)Chro
16、nic DiarrheaIntestinalinfections(T.B., Chronic bacteria dysentery, etc.)parasitics (Amebia dysentery, Giardiasis, etc.)IBD (ulcerative colitis, Chrons, etc.)malabsorption synd. (lactase deficiency, etc.)tumorsEndoscopic image: infectious colitis in 7-year-old girllower small bowel diseaseCrohns disease tuberculosis Yersinia enterocoliticaComplications of lower small bowel disease causing diarrhoea include:B12 deficiency bile acid wastingupper small bowel diseasecoeliac disease Giardiasis Whipple
