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

Diarrhea Definition increase in the frequency of bowel movements increase in stool liquidity in some cases increase in daily stool weight (>200g/d)

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)

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

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

Cholera: the simplified version

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).

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

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

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

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

osmotic diarrhoea disaccharidase deficiency  primarily lactase deficiency laxative abuse(about 20% of patients

Causes of diarrhea in enteral nutrition

Calculation of osmotic gap

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

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

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

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

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.

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

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.

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.)

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

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

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

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

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

gastric causes post gastrectomy post vagotomy gastrocolic fistula

pancreatic causes cystic fibrosis chronic pancreatitis pancreatic carcinoma

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

functional causes 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

classification of diarrhoeal disease by time-course acute chronic

Symptoms Acute diarrhea duration less than 2 weeks

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

Symptoms Chronic diarrhea duration more than 2 months

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

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

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

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

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.)

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

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.)

Lab findings Blood Urine Stool Microscopy Tolerance tests Breath tests Culture of Jejunal aspirates 5 HIAA (urinary excretion) Vit B 12 absorption test X-ray Barium Endoscopy Suction biopsy technique (Jejunal mucosa histology

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(-)

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

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

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

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 B 12 absorption test

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

CASE REPORT 女性,28 岁 反复腹泻 10 年 大便检查 : 常规, 脂肪,D- 木糖试验 生化 : 低白蛋白, 低钙, 贫血 …… 特殊检查 : 胃, 结肠, 小肠, 腹腔 小肠病变 : 胶囊内镜, 上下小肠镜 + 活检 治疗 : 激素有效