交通大学医学院附属 仁济医院消化科 上海市消化疾病研究所

1. 交通大学医学院附属仁济医院消化科上海市消化疾病研究所交通大学医学院附属仁济医院消化科上海市消化疾病研究所 范竹萍

2. Diarrhea Definition • increase in thefrequency of bowel movements • increase instool liquidity • in some cases increase in dailystool weight(>200g/d)

3. Pathophysiological mechanisms • secretory diarrhea (increased intestinal secretion) • Osmotic diarrhea • Decreased intestinal surface area and/or intestinal absorption • Inflammatary diarrhea • Rapid transit of intestinal contents (shortened transit time)

4. Pathophysiological mechanisms secretory diarrhea (increased intestinal secretion) activate Adenylate cyclase cAMP system NaCl secretory diarrhea agents • infections (cholera toxin, E-col, salmonella, staphylococcal) • Hormonal (Gut Hormones, ZES, VIP), cancer (calcitonin, Prostaglandins) • miscellaneous (laxatives abuse, villous adenoma of the rectum)

5. secretory diarrhoea • infection • cholera • hormonal • Verner-Morrison syndrome (VIP associated) • carcinoid syndrome • gastrinoma • medullary thyroid cancer • phenolphthalein abuse • bile salt malabsorption

6. Cholera: the simplified version

7. Verner-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 reduced total body potassium, and achlorhydria (metabolic acidosis).

8. carcinoid syndrome • paroxysmal 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 • pellagra-like lesions of the skin and oral mucosa

9. gastrinoma The Zollinger-Ellison syndrome describes the association of: • gastrin-producing tumours • gastric hypersecretion • severe peptic ulcer disease

10. gastrinoma • high fasting plasma gastrin • high gastric acid secretion • diminished response to pentagastrin • demonstrable 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 gastrinomas

11. Pathophysiological mechanisms Osmotic diarrhea It caused by accumulation of the followings in the gut lumen being osmotically active poorly absorble solutes maldigestion of ingested food failure to transport an osmotically active dietary nonelectrolyte (E: glucose) water salts diarrhea intestinal Lumen

12. osmotic diarrhoea • disaccharidase deficiency • primarily lactase deficiency • laxative abuse(about 20% of patients

13. Causes of diarrhea in enteral nutrition

14. Calculation of osmotic gap

15. Pathophysiological mechanisms Decreased intestinal surface area and/or intestinal absorption E: surgical removal; malabsorption syndrome

17. Pathophysiological mechanisms Rapid transit of intestinal contents (shortened transit time) increase in intestinal motility (intestinal hurry) contents reduce volume liquidity contact time increase stool small bowel mucosa E: irritable bowel syndrome [Functional diarrhea] laxatives abuse post vagotomy diarrhea post gastrectomy dumbing syndrome

18. Etiology Acute Diarrhea • infection • Food poisoning • Systematic diseases (influenza, sepsis, etc) • Miscellanous

19. Etiology Acute Diarrhea • infection 1.viral 2. bacterial • campylobacteria • Shigella • E. Coli • Salmoneila • etc 3.fungal 4.parasitic (amebic Trophozoites, Giardia)

20. Acute Diarrhea • Food poisoning • bacterial, plants, chemical poison(arsenic,...) • Systematic diseases (influenza, sepsis, measle, etc) • Miscellanous • Allergic diseases • Allergic purpura, enteropathy.. • endocronic diseases (ZES, etc.) • Drugs: laxatives, 5-Fu, etc.

21. food poisoning • bacterial • intrinsically poisonous food, for example deadly nightshade, red kidney beans • parasites in the meat, for example Taenia, Trichinella • chemicals • heavy metals, e.g. mercury, zinc • pesticides, e.g. rodenticides, insecticides • allergies • paralytic shell fish poisoning • scombrotoxin histamine intoxication • viral food poisonining • chinese restaurant syndrome - monosodium glutamate

22. chinese restaurant syndrome • Excess 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.

23. Etiology Chronic Diarrhea • Intestinal • Gastric(chronic gastritis,subtotal gastrectomy , etc.) • Pancreatic (Chronic Pancreatitis, Pancreatic Cancer, etc.) • Hepatobiliary(liver cirrhosis, obstructive jaundice) • functional causes • Endocronic (Hyperthyroids crisis, ZES, Carcinoids) • Drugs (Reserpin, Ismelin, Laxatives, etc.) • Others (uremia, hypogammaglobulemia, etc.)

24. Chronic Diarrhea • Intestinal • infections(T.B., Chronic bacteria dysentery, etc.) • parasitics (Amebia dysentery, Giardiasis, etc.) • IBD (ulcerative colitis, Chron’s, etc.) • malabsorption synd. (lactase deficiency, etc.) • tumors

25. Endoscopic image: infectious colitis in 7-year-old girl

26. lower small bowel disease • Crohn's disease • tuberculosis • Yersinia enterocolitica Complications of lower small bowel disease causing diarrhoea include: • B12 deficiency • bile acid wasting

27. upper small bowel disease • coeliac disease • Giardiasis • Whipple's disease • There may be steatorrhoea or a watery stool. Other complications include: • iron deficiency • folate deficiency • calcium deficiency

28. large intestine causes • dysentery • worms • inflammatory bowel disease • colonic carcinoma • irritable bowel syndrome • faecal impaction with overflow • radiation enteritis • diverticular disease • mesenteric ischaemia

29. gastric causes • post gastrectomy • post vagotomy • gastrocolic fistula

30. pancreatic causes • cystic fibrosis • chronic pancreatitis • pancreatic carcinoma

31. endocrine related • uraemia • thyrotoxicosis • carcinoid syndrome • Zollinger-Ellison syndrome • medullary carcinoma of the thyroid • hypoparathyroidism • diabetes mellitus, which may cause autonomic diabetic neuropathy, presenting with nocturnal diarrhoea • Verner-Morrison syndrome

32. functional causes irritable bowel syndrome • more than three motions per day • less than three motions per week • hard or lumpy stools • loose or watery stools • straining during a bowel movement • urgency • feeling of incomplete emptying • passing mucus during a bowel movement • abdominal fullness, bloating or swelling

33. classification of diarrhoeal disease by time-course • acute • chronic

34. Symptoms Acute diarrhea duration less than2 weeks

35. Acute diarrheaSymptoms • onset: • Abrupt frequent, small fecal discharge • Cramping abdominal pain, tenesmuse • stool: increased • Routin Ex severe cases: dehydration, electrolyte disturbances, metabolic acidosis, collapse hypovolumia, tetany. volume liquidity flecks of blood, mucus WBC, RBC, pus, destroyed epithelium

36. Symptoms Chronic diarrhea duration more than 2 months

37. Chronic diarrhea Symptoms • Onset: • gradual/insidious • Diarrhea of variable severity • Diarrhea alternate with constipation • Colicky abdominal pain, distention

38. intestinal causes in small bowel pathology: • abdominal pain, when present, is periumbilical or right iliac fossa • the frequency of defecation is often reduced • the stool may be well formed but it is bulky, offensive, and may be pale in colour • there may be signs and symptoms of malabsorption

39. intestinal causes in large bowel pathology: • there is often a defect in the reabsorption of water from the faeces • stools may be profuse and watery and/or mixed with blood and mucus • there may be lower abdominal pain with tenesmus and urgency

40. stool • watery, bloody, steatorrhea • contains: • inflammatory cells/mucus/pus/indigested food • severe/long-standing cases: • weight loss, malnutrition, edema, multy vits deficiency, malabsorption, wasting, edema, bone pain

41. Accompanied Symptoms • severe dehydration (cholera, pancreatic cholera-WDHA, etc.) • fever (Acute bacillery dysentery, Typhoid, TB enteritis, etc.) • tenesmus (Acute dysentery, proctitis, etc.) • markedly weight loss (cancer of gut, malabsorption, etc.) • Arthralgia/Arthritis (IBD, connective tissue diseases, etc.) • masses (malignant cancer of GI, TB, peritonitis, etc.)

42. Diagnostic Procedures • Information • P.E. Findings fever, dehydration, malnutrion, anemia, ulticaria, jaundice, arthralgia, abdominal masses, Tenesmus, digital rectal examination. • Lab findings

43. Diagnostic Procedures information • in epidemics (Dysentery, v. Cholerae, Typhoid, food poisonning, enteritis) • food allergy • past illness(antibiotic related diarrhea, etc.) • medication take(corticosteroids, laxatives, etc.) • predisposing conditions (surgical resection, parasitic infection, etc.)

44. Lab findings • Blood • Urine • Stool • Microscopy • Tolerance tests • Breath tests • Culture of Jejunal aspirates • 5 HIAA (urinary excretion) • Vit B12 absorption test • X-ray Barium • Endoscopy • Suction biopsy technique (Jejunal mucosa histology

45. investigations of diarrhoea • digital rectal examination, to exclude overflow diarrhoea due to constipation and a low rectal carcinoma • blood tests include • full blood count, ESR • creatinine and electrolytes, glucose • C reactive protein • clotting screen • B12 and folate • TIBC • thyroxine • immunoglobulins • fasting gut hormones - if other tests(-)

46. Lab findings • Urine • Protein • cast • Stool • appearance (watery, bloody, bulky, sticky, malodorous, steaterrhea, foul-smelling)

47. Lab findings • Microscopy RBC, WBC polymorphonuclear (PMN):Shigella, solmonella, E coli mononuclear (M) motile amebic trophozoites • Gram’s stain (+) staphylococcal enteritis • Culture: salmonolla, shigella, v. cholera • Fat determination

48. investigations of diarrhoea • radiology • especially important when the abdomen is distended or tender • a plain abdominal film may reveal fluid levels, gas- filled loops or loss of gas in parts where the loops are inflamed • barium enema • sigmoidoscopy +/- biopsy • colonoscopy +/- biopsy • stool microbiology, including microscopy, culture and antibiotic sensitivitydetermine • stool for faecal fat estimation to exclude steatorrhoea

49. Lab findings • Tolerance tests (d-xylose; Glucose/lactose/sucrose) • Breath tests 14C Glycine-cholate, xylose • Culture of Jejunal aspirates (Bacterial overgrowth) (increased Bile and deconjugation) • 5 HIAA (urinary excretion) • Vit B12 absorption test

50. differential diagnosis of diarrhoea • copious watery diarrhoea suggests an organic aetiology • nocturnal diarrhoea suggests an organic aetiology - patient wakes up in the night needing to open bowels • frequent passage of small amounts of faeces suggests functional bowel disease, e.g. irritable bowel syndrome • bloody diarrhoea implies colonic disease, often inflammatory bowel disease or carcinoma, or an invasive infective diarrhoea, e.g. Campylobacter jejuni • acute diarrhoea often has an infective aetiology