Diseases of the Intestines

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Diseases of the Intestines

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Diseases of the Intestines

• Overview
• Approach to acute diarrhea
• Chronic diarrhea localization
• Chronic diarrhea diagnostics

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GI cases on the web

• http//caltest.nbc.upenn.edu/sagastro

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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

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History

• Character of stool
• Color
• Fresh blood
• Melena
• Mucus
• Bulky/scant
• Alterations in shape
• Malodorous

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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

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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

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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?

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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

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Approach to Acute Diarrhea

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Approach to acute diarrheaMild 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

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Approach to acute diarrheaModerate to severe
diarrhea

• Classify as moderate/severe when there is
• Weakness
• Weight loss
• Fever
• Anorexia
• Depression
• Significant dehydration
• Abdominal pain
• Abdominal mass

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Diagnostic approach to acute diarrheaModerate
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)

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Approach to Chronic Diarrhea

• Localization

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• location, location, location.

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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

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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

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Approach to Malassimilation

• Maldigestion
• Exocrine pancreatic insufficiency
• Brush border enzyme deficiency

• Malabsorption
• Many causes
• Is PLE present?

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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

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Protein losing enteropathy (PLE)

• Reasons for excessive enteric protein loss
• Impaired intestinal lymphatic drainage
  (lymphangiectasia)
• Disruption of mucosal barrier (severe
  inflammation)

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Protein losing enteropathy (PLE)

• Most commonly occurs with
• Lymphangiectasia
• IBD
• Intestinal lymphosarcoma
• Intestinal histoplasmosis

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Approach to Chronic DiarrheaDiagnostics

• CBC
• Biochemistries
• UA
• Fecal examinations
• FeLV, FIV (cats)
• T4 (older cats)

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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

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More Fecal Examinations

• Fecal bacteriology screen
• Salmonella
• Campylobacter
• Clostridium
• Yersinia
• Specific E. coli subtypes

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More Fecal ExaminationsSpecial Stains

• Tests for malassimilation
• Sudan stain (fats)
• Lugols iodine stain (starch)
• (plasma turbidity test)
• Cytology (Diff-Quik, Wrights or NMB)
• Look for inflammation, neoplasia, histoplasmosis,
  certain bacterial populations
• Gram stain

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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)

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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

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Other serum tests for evaluation of intestinal
disease

• Plasma turbidity test
• Screening test for lipid maldigestion or
  malabsorption
• Relatively insensitive

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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

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Ultrasonography

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Endoscopy

• Gastroduodenoscopy
• and/or colonoscopy
• Visual inspection
• Mucosal biopsy
• Duodenal aspiration

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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)

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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

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Exploratory Laparotomy

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

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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

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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)