L23-Chronic Diarrhea Year 4 Internal Medicine Notes

L23-Chronic Diarrhea Year 4 · Internal Medicine Collection: 4TH YEAR ALL NOTES / IMED / I MED BEAUTIFUL NOTES / GIT -- Lecture 23 \nEditing file\n\n Chronic Diarrhea \nObjectives:\n★ To have an overview regarding chronic diarrhea:\n○ Definition.\n○ Pathophysiology.\n○ Classification.\n○ Approach.\n★ To discuss common causes of chronic diarrhea:\n○ Celiac Disease.\n○ Whipple Disease.\n○ Tropical Sprue.\n○ Small Bowel Bacterial Overgrowth.\n○ Exocrine Pancreatic Insufficiency.\n○ Bile Salt-Induced Diarrhea.\n\n Color index: Color index:\nOriginal text Females slides Males slides\nDoctor’s notes Text book Important Golden notes Extra \n\n Diarrhea 2\n\n◄ Definitions ➔ Diarrhea: A change in consistency (subjectively\nbecome loose) or volume of liquid in the stool or\nincreased frequency ➔ Acute Diarrhea: <2 wks (Usually due to infectious\ncauses) ➔ Subacute Diarrhea: 2-4wks ➔ Chronic Diarrhea: 4-6 wks ➔ Maldigestion: Inadequate breakdown of large\nmolecules. ➔ Malabsorption: Inadequate mucosal transport of\ndigested products to the blood stream\n\n◄ Pathophysiology\n\n A normal colon can\nThe colon absorbs 90% of the\ncompensate (if there is Each day, 9–10L of fluid enter remaining load (about 900 ml/24\ndiarrhea) by absorbing up the jejunum. Small intestine hours); leaving approximately\nto 3000–4000 ml/24 hours. absorbs 90% of this fluid load. 80–100 ml excreted each day in\nthe colon can’t adapt for\nfeces. (normal)\nmore than 4L\n\n So, Which one will cause LARGE VOLUME diarrhea; Small or large bowel disease?\n➢ Small bowel, because normally it absorb most of the fluid (9L)\n\n◄ Classification of Diarrhea\nFatty\nNon-inflammatory Secretory\nDiarrhea\n\n Watery\nOsmotic\n\n OVERVIEW:\nInflammatory - Sudden onset of bowel frequency associated with crampy\nabdominal pains, and a fever, will point to an infective cause\n- bowel frequency with loose, blood-stained stools to an\ninflammatory basis\n- The passage of pale, offensive stools that float, often\naccompanied by loss of appetite and weight loss, to steatorrhoea. \n\n Common medications and toxins 3 \nassociated with diarrhea ◆ Acid-reducing agents (H2 blockers, PPIs). ◆ Furosemide. ◆ Magnesium-containing antacids. ◆ Metformin. ◆ Antiarrhythmics (eg, digitalis, quinidine). ◆ NSAIDs, ASA. ◆ Antibiotics. ◆ Prostaglandin analogs (ie, misoprostil). ◆ Antineoplastic agents. ◆ Theophylline. ◆ Antiretrovirals. ◆ Amphetamines. ◆ Beta blockers. ◆ Caffeine. ◆ Colchicine. ◆ Alcohol. ◆ Levothyroxine. ◆ Narcotic/opioid withdrawal. ◆ SSRIs. ○ Narcotic it self can cause constipation,\nafter withdrawal Diarrhea ensue\n\n 1) Watery Diarrhea \nOsmotic Diarrhea ◆ Poorly absorbed substances that remain in the lumen of the intestine and obligate retention of\nwater within the lumen by virtue of their osmotic effects ◆ Osmotic diarrhea is RELIEVED by fasting ◆ Fecal osmotic Gap = 290 - 2( stool Na + stool k )\n○ 50 mOsm/Kg is Suggestive of an osmotic diarrhea\n○ 100 mOsm/Kg is more specific (Definitive!)\n\n Ingestion of poorly absorbed agent Loss of nutrient transporter \n➥ Carbohydrate malabsorption: diet high\n➥ Lactose intolerance (due to\nin Fructose or sugar alcohols\nlactase deficiency)\n➥ Diuretics: Mannitol\n➥ Disaccharidase deficiency\n➥ Osmotic laxatives: Magnesium,\n➥ Glucose-galactose\nphosphate, sulfate, sorbitol, lactulose\nmalabsorption \n\n 1) Watery Diarrhea 4\n\n Secretory Diarrhea\n◆ There is both active intestinal secretion of fluid and electrolytes, and decreased absorption. How to differentiate between Osmotic and Secretory?\n1) Diagnostic fast test: Osmotic diarrhea is RELIEVED by fasting, while secretory diarrhea\ndoes NOT respond to fasting!\n2) Fecal osmotic gap:\na) 100 mOsm/kg → Osmotic diarrhea\nb) <50 mOsm/kg → Secretory diarrhea\n\n Causes include:\n\n1 Infections: The most common\ncause is a bacterial toxin.\n2 Pancreatic insufficiency\n3 Inflammation & Dysregulation:\nDiverticulitis, Vasculitis,\nmicroscopic colitis,\n\n4\nGastroenteritis\n\n Absence of an ion-transport\nmechanism.\n5Reduction of mucosal surface area\nby surgery or disease.\n6 Congenital chloridorrhea\n\n7 Bile Acid induced diarrhea: Ileal\nbile acid malabsorption.\n8 Idiopathic: Epidemic (Brainerd),\nSporadic.\n9 Medications (NSAIDs, Colchicine),\nstimulant laxative abuse, toxins.\n\n10 Malignancy: Colon CA,\n11 Abnormal motility: DM-related\n12 Circulting secretagogues\n(endocrinopathies): as in\nAddison's disease,\nlymphoma, rectal villous dysfunction, IBS, Hyperthyroidism, Carcinoid\nadenoma Post-vagotomy diarrhea. syndrome, Pheochromocytoma,\nGastrinoma (a.k.a ZE syndrome)\nVIPoma, Somatostatinoma.\n\n An area for your notes \n\n 2) Fatty Diarrhea (Steatorrhea) 5\n\n ● Present with Bloating, flatulence, greasy malodorous stools that is foul smelling and\ndifficult to flush\n● Weight loss, s/s of vitamin deficiencies1 (peripheral neuropathy, easy bruising)\n● Iron deficiency anemia, coagulopathy, hypoalbuminemia, osteopenia.\n\n Malabsorption\nMaldigestion\ninadequate mucosa