II. Epidemiology

  1. Age: 10 to 40 years old
  2. First degree relative with Inflammatory Bowel Disease increases risk 10 fold

III. Differential Diagnosis

  1. Lower GI Bleeding
    1. Diverticulitis (most common cause)
    2. Angiodysplasia (Arteriovenous Malformation)
    3. Neoplasm
    4. Ulcerative Colitis (Blood Diarrhea distinguishes from Crohn's Disease)
    5. Ischemic Colitis (Older patients with sudden onset pain)
    6. Anorectal Disease
      1. Hemorrhoids
      2. Anal Fissures
  2. Diarrhea
    1. Non-Infectious Osmotic Diarrhea
    2. Non-Infectious Secretory Diarrhea
    3. Ulcerative Colitis (bloody Diarrhea)
    4. Crohn's Disease
    5. Irritable Bowel Syndrome (diagnosis of exclusion)
    6. Fecal Impaction (with leakage)
    7. Infectious Diarrhea (Sudden onset and often painful)
      1. Pseudomembranous colitis of Clostridium difficile (recent antibiotic use)
      2. Entamoeba histolytica
      3. Tuberculosis
      4. Cytomegalovirus
      5. Yersinia
      6. Strongyloides

IV. History

  1. Travel
  2. Contaminated intake
    1. Foodborne Illness
    2. Waterborne Illness
  3. Immunodeficiency risk
  4. High risk sexual behavior
  5. Family History of Gastrointestinal disease
  6. Medications in the last 6 months (e.g. antibiotics)

V. Symptoms

  1. Chronic Inflammatory Diarrhea
    1. Crohn Disease may also cause Secretory Diarrhea (Chronic Watery Diarrhea)
  2. Pain
    1. Ulcerative Colitis
      1. Lower abdominal cramps
      2. Relieved with Bowel Movement
    2. Crohn's Disease
      1. Constant pain often in right lower quadrant
      2. Not relieved with Bowel Movement
  3. Stool Blood
    1. Grossly bloody stool in Ulcerative Colitis

VI. Signs

  1. Abdominal Mass
    1. Ulcerative Colitis: No abdominal mass
    2. Crohn's Disease: Mass often at Right lower quadrant
  2. Gastrointestinal Tract Affected
    1. Ulcerative Colitis
      1. Affects only colon
      2. Continuous from Rectum
    2. Crohn's Disease
      1. Mouth to anus potentially affected
      2. Discontinuous, "Skip" lesions
  3. Bowel Tissue affected
    1. Ulcerative Colitis: Mucosal disease (no Granuloma)
    2. Crohn's Disease: Transmural disease (Granulomas)

VIII. Labs: Stool Studies

  1. Fecal Calprotectin
    1. Newer test with high Test Sensitivity and Test Specificity for Inflammatory Bowel Disease
    2. Fecal Calprotectin <40 mcg/g and CRP <0.5 reduce Inflammatory Bowel Disease likelihood to<1%
      1. Menees (2015) Am J Gastroenterol 110(3):444-54 [PubMed]
  2. General Stool studies
    1. Stool Culture
    2. Stool for Ova and Parasites
    3. GiardiaAntigen
    4. Clostridium difficile Toxin and culture
    5. Fecal Leukocytes
  3. Additional Stool studies
    1. Yersinia enterocolitica culture
    2. Toxigenic Escherichia coli isolation
    3. Entamoeba histolytica serologic titers

XI. Differential Diagnosis: Distinguishing Crohn's Disease from Ulcerative Colitis

  1. Location
    1. Crohn's Disease can involve any area of Gastrointestinal Tract (most common in ileocolic region)
    2. Ulcerative Colitis is typically limited to colon, and has onset at the Rectum
  2. Thickness
    1. Crohn's Disease involves the entire bowel wall
    2. Ulcerative Colitis is limited to the mucosa and submucosa
  3. Colonoscopy
    1. Crohn's Disease demonstrates skip lesions, cobblestoning, ulcerations and strictures
    2. Ulcerative Colitis demonstrates pseudopolyps, continuous areas of inflammation
  4. Other discriminating factors
    1. Anemia is more common in Ulcerative Colitis
    2. Abdominal Pain is more common in Crohn's Disease
    3. Anorexia and weight loss is common in Crohn's Disease
    4. Rectal Bleeding is more common in Ulcerative Colitis (bloody Diarrhea is a common presentation)
    5. Colon Cancer is much more common in Ulcerative Colitis

XII. Diagnosis

  1. Colonoscopy with mucosal biopsy

XIII. Imaging

  1. CT Abdomen and Pelvis (or MRI Abdomen)
    1. Undifferentiated Inflammatory Bowel Disease (prior to diagnosis)
    2. Known Inflammatory Bowel Disease with complication
      1. Small Bowel Obstruction
      2. Sepsis with suspected intraabdominal source
      3. Perianal Sepsis
  2. Abdominal XRay findings (if done for other reasons)
    1. Perforation signs (i.e. Free air in peritoneum)
    2. Toxic Megacolon
    3. Thumb-printing
      1. Pattern of multiple locations where bowel wall appears indented (as if by a thumbs)

XIV. Management

  1. See Ulcerative Colitis (bloody Diarrhea)
  2. See Crohn's Disease
  3. See Microscopic Colitis
  4. Precautions
    1. Consult gastroenterology in acute presentations prior to diagnosis and in exacerbations
    2. Avoid management (e.g. Corticosteroids) that interfere with diagnosis prior to definitive study (e.g. Colonoscopy)
    3. Exclude infection (e.g. C. difficile and other enteric Bacterial Infection) pre-diagnosis and with exacerbations
  5. Symptom management in formally diagnosed Inflammatory Bowel Disease (e.g. prior Colonoscopy with biopsy)
    1. Avoid starting Corticosteroids unless infection has been excluded, IBD cause is known and GI consultant agrees
    2. Ongoing Inflammatory Bowel Disease management may be adjusted
      1. Patients with increased symptoms on a Corticosteroid taper could return to the prior dose
      2. Patients on 5-Aminosalicylic Acid could have dosing maximized or add rectal enema (4 g)

XV. Resources

  1. Crohn's and Colitis Foundation of America
    1. http://www.ccfa.org
  2. Cedars-Sinai Inflammatory Bowel Disease Center
    1. http://www.csmc.edu/ibd

XVI. References

  1. Cardy and Williams in Swadron (2022) EM:Rap 22(7): 15-7
  2. McDowell (2022) Inflammatory Bowel Disease, StatPearls, Treasure Island
    1. https://www.ncbi.nlm.nih.gov/books/NBK470312/

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