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Diarrhea- C. diff. Is Negative – Now What?

Erin Jenkins Wessling

Erin.jenkins@alegent.org

Division of Gastroenterology

Objectives:

• Understand when laboratory evaluation is indicated in acute diarrhea

• Review important history aspects in evaluation of chronic diarrhea

• Discuss common causes of osmotic diarrhea

• Recognize “red flags” that prompt further evaluation and referral

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Definition

• Diarrhea: 3 or greater bowel movements per day of loose consistency • Alternate definition by weight - > 200 g / day,

• Acute Diarrhea: • for ≦14 days

• Chronic Diarrhea• Diarrhea for ≧ 30 days

Physiology in health:

• 9-10 L fluid enters jejunum daily (salivary, gastric pancreatic, and biliary secretions)

• 90% absorbed in small bowel

• 800-1000 mL enters colon

• 90% absorbed on colon – 100 mL excreted in stool

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Acute Diarrhea

• Typically infectious, esp. viral

• supportive care/ oral hydration

• No workup unless C. diff suspicion, dysenteric (blood), high risk traveler, or moderate to severe with fever, symptoms > 7 days

• Exception for “public health situation”

American College of Gastroenterology Clinical Guideline: Diagnosis, Treatment, and Prevention of Acute Diarrheal Infections in Adults - May 2016

GI Pathogen Panel

• Culture independent methods preferred

• C. difficile can be false positive

• Will this change management?

• Avoid O and P if no travel/ immigration history

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Chronic Diarrhea Evaluation

1. Take a good history

• frequency/ consistency

• Pain

• Blood

• Nocturnal symptoms

• Triggers: food, stress?

• Weight loss

• Medications/ supplements

Chronic Diarrhea Evaluation

2. Perform a good physical exam• Weight change• Nutritional status/ appearance• Rectal exam for select patients

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Chronic Diarrhea Evaluation

3. Identify “red flags” that proceed directly to colonoscopy +/- endoscopy or clinic referral

• Blood, nocturnal bowel movements, significant weight loss, behind on colorectal cancer screening, iron deficiency anemia

Chronic Diarrhea Evaluation

4. Consider non – invasive workup; if positive, proceed to further testing:

• CBC, CMP, CRP, celiac testing ( tTGIgA, IgA), TSH

• Fecal calprotectin

• Other stool testing ( stool electrolytes)

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Chronic diarrhea – history clues

• Verify if true diarrhea vs. incontinence of formed stool/ frequent passage hard stool

• Diarrhea alternating with constipation and associated with pain, no “red flags” = irritable bowel syndrome

• Blood suggests infectious or inflammatory

• Nocturnal indicates possible secretory/ inflammatory and needs workup

• Weight loss and laboratory/ clinic evidence of malabsorption suggests organic problem – not function/ irritable bowel and not dietary

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Case Follow Up

• Blood work showed mild iron deficiency anemia, tTGA positive at 125 ( normal less than 8).

• EGD with duodenal biopsies confirmed Celiac disease

• Doing well at 3 month f/u –tTGA normal

Celiac Disease Clinical Pearls

• Diagnosis with positive labs AND confirmatory biopsies on gluten FULL diet

• Can be missed at EGD unless proper duodenal biopsies taken ( high suspicion)

• Treatment with gluten free diet

• Dietitian consult, check vitamin/ mineral levels, annual celiac serologiesonce normal, bone mineral density screening

• tTGA / serum IgA screening ( don’t need full panel)

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Clinical Case #2

• Intermittent diarrhea is often dietary (osmotic)

• Patient was drinking Dr. Pepper while working to stay awake (high fructose corn syrup)

• Decreased rectal tone made symptoms more extreme

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Clinical Case 2 – Osmotic diarrhea

• Lactose and high levels of fructose are main offenders

• Sugar alcohols ( sorbitol, etc).

• Low FODMAP diet eliminates fermentable sugars from diet

• Low FODMAP studied in IBS –D, helpful in functional diarrhea

AGA patient education page

Osmotic vs. Secretory• Stool osmotic gap= 290 mosm/kg – 2 ( stool Na + K)

Osmotic Secretory

Osmotic gap > 100 <50

History Usually resolves with fasting

-Persists even with fasting-high volume, sometimes electrolyte disturbance

Common Causes -Lactose, fructose, sucrose intolerance-Mag. Antacids or Mag supplements-Sorbitol, Xylitol, sucralose,

-Infections-Bile salt/ acid-Neuroendocrine-Microscopic colitis -Diabetic diarrhea

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Clinical Case #3 – C. Diff is negative…

Colon biopsies show microscopic colitis-2 subtypes behave similarly, different microscopic appearance- QOL disease – no progression or

malignancy risk

Up To Date - images

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Clinical Case # 3 – Microscopic Colitis

• Most commonly in elderly females

• NSAID, PPI, SSRI medications increase risk

• Treated with budesonide, topical corticosteroid x 8 weeks

• 1/3 will not need further treatment, 2/3 may need maintenance or recurrent treatment

• Increased risk among those with celiac

• Not evaluated at “screening colon” – need random biopsies

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Clinical Case #4

• Fecal calprotectin – measures a protein in neutrophils – marker in inflammation

• Good for “ ruling out” IBD

• 93% sensitive, 94 % specific for Crohn’s or ulcerative colitis

• May be less sensitive for isolated ileal disease

• All positive tests should be followed up with colonoscopy

De’Angelo et al. Digestion 2017.

Irritable Bowel Syndrome - Diarrhea

• If no red flags, don’t need investigation other than r/o celiac disease • ( all testing done would be negative) • Treatment of IBS – D in past has included:

• Dietary modification • Anti-motility – loperamide• Fiber for stool bulking • Tri-cyclic anti-depressant • Antispasmotic ( dicyclomine/ hyoscyamine) – help with cramping and decrease

motility • Non – absorbable antibiotic ( rifaxamin)• Eluxadoline

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Diarrhea Clinical Pearls

• Good history and physical paramount

• For acute severe diarrhea, PCR based stool testing preferred over culture or O and P

• Make sure celiac testing is done before going gluten free

• Osmotic diarrhea from diet or meds is common; low FODMAP diet may be helpful

• Microscopic Colitis is diagnosed only when colonic biopsies taken

• Fecal calprotectin can be helpful non – invasive method of excluding IBD

Sources:

• Schiller et. al. Clin Gastroenterol Hepatol. 2017 Feb; 15(2) 182-193