Diseases of the Intestines

1. Diseases of the Intestines

2. Diseases of the Intestines Overview Approach to acute diarrhea Chronic diarrhea � localization Chronic diarrhea � diagnostics

3. GI cases on the web http://caltest.nbc.upenn.edu/sagastro

4. Diarrhea: Physiology Diarrhea: Increase in the frequency, fluidity, and volume of feces Deranged transmucosal water and electrolyte fluxes caused by one or more of: Maldigestion Malabsorption Abnormal secretory activity Increased permeability Abnormal motility

5. History Character of stool Color Fresh blood Melena Mucus Bulky/scant Alterations in shape Malodorous

6. History Onset, duration, progression Intermittent/continuous Frequency of defecation Volume of stools Urgency of defecation Tenesmus Flatulence Borborygmus Vomiting Weight loss Usual diet and response to any diet changes Supplements or drugs Response to any therapies Systemic signs

7. Physical examination Complete physical examination Particular attention to: BCS Hydration status Abdominal palpation Apparent pain Gas- or fluid-filled bowel loops Mass or abnormal bowel loop Rectal examination

8. Questions to keep in mind when examining a patient with diarrhea Primary or secondary GI? Acute or chronic? Chronic if lasts longer than 3-4 weeks or has episodic recurrence Small bowel or large bowel? Severity: Mild or moderate/severe? Infectious cause or zoonosis likely?

9. Fecal floatation The minimum laboratory evaluation for ALL patients with diarrhea If negative, repeat twice more Zinc sulfate centrifugation preferable to fecal floatation Consider therapeutic deworming for mild diarrhea in young animals Use sample for visual inspection

10. Approach to Acute Diarrhea

11. Approach to acute diarrhea:Mild diarrhea Classify as �mild� if: Normal attitude No weight loss No palpable abnormalities Dietary management as for acute gastroenteritis case except: If no concurrent vomiting, recommend �feeding through� the diarrhea with a bland, highly digestible diet Manage fluid deficit and needs Antidiarrheal for owner and/or patient comfort

12. Approach to acute diarrhea:Moderate to severe diarrhea Classify as �moderate/severe� when there is: Weakness Weight loss Fever Anorexia Depression Significant dehydration Abdominal pain Abdominal mass

13. Diagnostic approach to acute diarrhea:Moderate to severe diarrhea Indicated in most cases: CBC Biochemistries UA Fecal Fecal cytology T4, FeLV, FIV (cats) Re-palpate abdomen at intervals Indicated in some cases: CITE test for parvovirus Fecal microscreen Coagulation status (if melena) Abdominal radiographs and/or ultrasound (If apparent pain or suspect mass)

14. Approach to Chronic Diarrhea Localization

15. �location, location, location�.

16. Localization of Diarrhea SMALL BOWEL May have weight loss Normal to slightly increased frequency Large volumes No tenesmus Melena LARGE BOWEL No weight loss Greatly increased frequency Small volumes Tenesmus Hematochezia

17. Localization of Diarrhea SMALL BOWEL No mucus �Cow pie� Steatorrhea Dehydration Weakness, lethargy, vomiting, ascites, borborygmus, fluid and acid-base changes LARGE BOWEL Mucus Loose to semi-formed, jelly-like No steatorrhea No dehydration Other signs: anal irritation, vomiting

19. Approach to Malassimilation Maldigestion Exocrine pancreatic insufficiency Brush border enzyme deficiency Malabsorption Many causes Is PLE present?

20. Protein losing enteropathy (PLE) A syndrome caused by a variety of small intestinal diseases that is characterized by panhypoproteinemia due to an accelerated loss of plasma proteins into the gut Note: GI loss normally accounts for about 40% of the daily turnover of plasma proteins May result in edema and ascites

21. Protein losing enteropathy (PLE) Reasons for excessive enteric protein loss Impaired intestinal lymphatic drainage (lymphangiectasia) Disruption of mucosal barrier (severe inflammation)

22. Protein losing enteropathy (PLE) Most commonly occurs with: Lymphangiectasia IBD Intestinal lymphosarcoma Intestinal histoplasmosis

23. Approach to Chronic Diarrhea:Diagnostics CBC Biochemistries UA Fecal examinations FeLV, FIV (cats) T4 (older cats)

24. Fecal Examinations Visual inspection Fecal floatation (helminth ova) Zinc sulphate centrifugation (giardia cysts) Saline fecal smear (trophozoites) Fecal cytology (+/- rectal scraping) CITE test for parvovirus (IDEXX) Fecal virology screen and/or EM

25. More Fecal Examinations Fecal bacteriology screen Salmonella Campylobacter Clostridium Yersinia Specific E. coli subtypes

26. More Fecal Examinations:Special Stains Tests for malassimilation Sudan stain (fats) Lugol�s iodine stain (starch) (plasma turbidity test) Cytology (Diff-Quik, Wrights or NMB) Look for inflammation, neoplasia, histoplasmosis, certain bacterial populations Gram stain

27. Still More Fecal Examinations Fecal occult blood Fecal proteolytic activity to detect EPI* Xray film digestion Gel slant digestion *Test of choice is Serum TLI (trypsin-like immunoreactivity)

28. Serum tests for evaluation of intestinal disease Serum folate* Absorbed in proximal SI Increased in bacterial overgrowth Decreased in malabsorption Serum cobalamin (B12)* Active absorption in ileum Decreased in bacterial overgrowth, malabsorption, and exocrine pancreatic insufficiency TLI Decreased in EPI, increased in pancreatitis *Both tests have low sensitivity

29. Other serum tests for evaluation of intestinal disease Plasma turbidity test Screening test for lipid maldigestion or malabsorption Relatively insensitive

30. Radiography Survey films and barium contrast series usually have low diagnostic yield in cases of chronic diarrhea Useful for masses, strictures, or other partial obstructions

31. Ultrasonography

32. Endoscopy Gastroduodenoscopy and/or colonoscopy Visual inspection Mucosal biopsy Duodenal aspiration

33. Patient Preparation for Gastroduodenoscopy No food for 12-18 hours No water for 4 hours Do not perform within 12-24 hours of a barium series (unless FB seen)

34. Patient Preparation for Colonoscopy No food for 24-36 hours EITHER Administer oral colonic lavage solution orally (OCL or GoLYTELY); 2 doses by stomach tube the day before the procedure, third dose 2-4 hours before �High� enema 2 hours before procedure OR 2 enemas the day prior to the procedure and a �high� enema 2 hours before procedure

35. Exploratory Laparotomy Full thickness biopsies of the stomach and small intestine Mass or lesion resection Mesenteric LN biopsies Duodenal aspiration Jejunostomy tube placement

36. Other GI function tests (available at selected institutions or under development) Breath hydrogen testing Hydrogen not produced by mammalian cells Oral administration of a sugar solution results in bacterial metabolism of some CHO leads to release of hydrogen; some is absorbed and carried to lungs from where is expired Collect expired gases at timed intervals and compare to standard curve

37. Other GI function tests (available at selected institutions or under development) Oral administration of radiolabelled chromium to assess intestinal mucosal integrity (more absorbed and excreted in urine if mucosal permeability increased) Permeability testing by inert sugar analysis (different molecular size inert sugars pass through pores of different sizes and urine concentrations measured at defined times) Serum total unconjugated bile acids (intestinal bacteria deconjugate bile acids)