Chronic diarrhea

Presentation on approach to Chronic Diarrhea

1. CHRONIC DIARRHEA Preceptor : Dr Nishav Raj Shahi Presenter : Dr Parash mani Bhatta

2. Duration : 30 minutes Objectives : At the end of session , participants will be able to know how to approach the case of chronic diarrhea

3. CONTENT 1. DEFINITION 2. ETIOLOGY 3. APPROACH 4. MANAGEMENT

4. Definition : P ersistent alteration of stool consistency and increase stool frequency of greater than 4 weeks duration.

5. Causes of Chronic diarrhea Secretory : -Derangement in fluid and electrolytes transport. -Watery and non bloody large volume fecal outputs that are typically painless and persist with fasting. -No fecal osmotic gap. Fecal osmotic gap: serum osmolarity (290 mosmol /kg) – { 2 * ( fecal sodium + potassium concentration)}

6. Exogenous stimulant laxatives( senna , cascara , bisacodyl ) Chronic ethanol ingestion. Endogenous laxatives ( dihydroxy bile acids ) Bowel resection, disease or fistula ( decrease absorption) – Worsens with eating.

7. Bile acid diarrhea : resection of < 100cm of terminal ileum , dihydroxy bile acids may escape absorption and stimulate colonic secretion ( cholerheic diarrhea ). - Bile acids are functionally malabsorbed from a normal appearing terminal ileum

8. Hormone producing tumor ( carcinoid, VIPoma , Medullary cancer thyroid , mastocytosis , gastrinoma , colorectal villous adenoma) Addison disease Oral angiotensin receptor blocker , olmesartan .

9. 2 ) Osmotic : -Poorly absorbable osmotically active solutes draw enough fluid into lumen to exceed reabsorptive capacity of colon . -Fecal osmotic gap ( >50 mosmol /L) -Fecal water output increases . -Less voluminous . - Caeses with fasting/discontinuation of causitive agent . Osmotic laxatives( Magnesium, phosphate and sulfate) Lactase deficiency Gluten and FODMAP intolerance Nonabsorbable carbohydrates ( sorbitol, lactulose, polyethylene glycol)

10. 3) Steatorrheal : - Steatorrhea is defined as stool fat exceeding normal 7g/day Intraluminal maldigestion ( pancreatic exocrine insufficiency- chronic pancreatitis, bacterial overgrowth, bariartic surgery, liver disease) M ucosal malabsorption ( celiac sprue , whipple’s disease, infections, abetalipoprotenemia , drug induced enteropathy , ischemia) Post mucosal lymphatic obstruction

11. 4) Inflammatory: -Characterized by pain , fever and bleeding. Idiopathic inflammatory bowel disease ( crohn’s disease, ulcerative colitis) Infection ( Selective IgA deficiency or common variable hypogammaglobulinemia , eosinophilic gastroenteritis, history of clostridiodes infection, invasive bacteria , viruses and parasites, Brainerd diarrhea) Gastrointestinal malignancies Radiation injury

12. 5) Dysmotility Irritable bowel syndrome. Carcinoid syndrome. Hyperthyroidism. Drugs ( prokinetic agents). Postvagotomy .

13. 6) Factitial : Munchausen ( self injury for secondary gain) Eating disorders

14. 7) Iatrogenic: Cholecyctectomy Ileal resection Bariartic surgery Vagotomy , fundoplication

15. Approach to the patient History Characterstic symptoms: Stool characterstics - Fat malabsorption -Greasy stools that float and malodorous. Inflammatory cause : presence of visible blood. Carbohydrate malabsorption (lactose): watery diarrhea , excess flatus and bloating .

16. Duration of symptoms , nature of onset ( sudden or gradual ) Diarrhea during fasting or at night suggests secretory or inflammatory diarrhea . Voluminous watery diarrhea- disorder in small bowel. small volume frequent diarrhea - disorders of colon. Presence of bloody diarrhea favors colonic versus small bowel disorder.

17. Stool characterstics and determining their source source : medscape Stool characteristics Small bowel Large bowel Appearance Watery Mucoid and/or bloody Volume Large Small Frequency Increased Highly increased Blood Possibly positive but never gross blood Commonly gross blood pH Possibly <5.5 >5.5 Reducing substance Positive Negative WBCs <5/high power field >10/high power field Serum WBC Normal Leukocytosis

18. W eight loss and fever, joint pain , mouth ulcers , eye redness indicate IBD Association of stress and depression : Irritable bowel syndrome(IBS) IBS – chronic abdominal pain and diarrhea , constipation or normal bowel habits alternating with either diarrhea or constipation

19. Physical examination Features to suggest malabsorption or inflammatory bowel disease such as anemia , dermatitis herpetiformis , edema or clubbing. Look for autonomic neuropathy, collagen vascular disease in pupils , orthostasis , skin, hands or joints? Abdominal mass or tenderness

20. Abnormalities of rectal mucosa , rectal defects or altered anal sphincter functions? Mucocutaneous manifestation of systemic disease: - dermatitis herpetifomis ( celiac disease), - erythema nodusum ( ulcerative colitis), - flushing (carcinoid) or -ulcers for IBD or celiac disease?

21. Evaluation of alarm features : suggestive of underlying organic etiology. Age of onset after age 50 Rectal bleeding or melena, Nocturnal pain or diarrhea Progressive abdominal pain Unexplained weight loss, fever, systemic symptoms Laboratory abnormalities( iron deficiency anemia, elevated C-reactive protein or fecal calprotectin ) Family history of inflammatory bowel disease or colorectal cancer

22. Source: uptodate

23. Complications Rapid dehydration Intussusception Gram-negative sepsis Hemolytic-uremic syndrome (HUS) Hemorrhagic colitis

24. Management of chronic diarrhea Step 1 : E xclude iatrogenic problem: medication , surgery Step 2 : A) B lood per rectum - Colonoscopy + biopsy B) F atty diarrhea – small bowel (imaging, biopsy, aspirate) C) N o blood , features of malabsorption - consider functional diarrhea – dietary exclusion of lactose , sorbitol .

25. D) Pain aggravated before Bowel movement , relieved with bowel movement , sense incomplete evacuation- suspect irritable bowel syndrome Limited screen for organic disease: Hematology, chemistry, CRP, ESR, Iron, folate , B12, TTG- igA , C4, Stool for excess fat, calprotectin Low hemoglobin, Albumin: abnormal MCV,MCH: excess fat in stool Low serum potassium Stool volume, osmotic, pH; laxative screen; hormonal screen Colonscopy + biopsy Small bowel: x-ray, biopsy aspirate: stool 48h fat Stool fat >20g/day: pancreatic function Stool fat 14-20g/day: search for small bowel cause Normal and stool fat < 14g/day Titrate treatment to speed of transit

26. Screening test all normal Opiod treatment plus follow up Persistent chronic diarrhea Full gut transit 48 hour stool bile acid Titrate treatment to speed of transit Bile acid sequestrant

27. Treatment For all patients with chronic diarrhea fluid and electrolyte replacement is a must. Curative Re secti on of colorectal cancer Antibiotic administration for Whipple’s disease or tropical sprue , or discontinuation of drug.

28. Supressive Elimination of dietary lactose for lactase deficiency Elimination of Gluten for celiac sprue , Glucocorticoids for idiopathic IBDs, B ile acid sequestrants for bile acid malabsorption , PPIs for gastric hypersecretion of gastrinomas , Octreotide for malignant carcinoid syndrome, I ndomethacin for medullary carcinoma thyroid, Pancreatic enzyme replacement for pancreatic insufficiency. Ppi -proton pump inhibitors

29. Empirical therapy : Mild/moderate watery diarrhea - Opiates such as diphenoxylate or loperamide . Severe diarrhea- codeine or tincture of opium (Avoid Antimotility agents in severe IBD because of risk of toxic megacolon ) Clonidine- control of diabetic diarrhea . Ondensetron , Alosetron - relieve diarrhea and urgency in IBS. Also rifaximin and eluxadoline for IBS Replacement of fat soluble vitamins in patients with chronic steatorrhea . IBD- inflamatory bowel disease , IBS- irritable bowel syndrome

30. SOURCE Harrison’s Principles Of Internal Medicine, -20 th edition . UpToDate . Medscape.

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