II. Epidemiology

  1. Age: 10 to 40 years old
  2. Prevalence of Inflammatory Bowel Disease: 3.1 Million in U.S.
  3. First degree relative with Inflammatory Bowel Disease increases risk 10 fold
    1. More common in caucasian patients
    2. More common in Ashkenazi Jewish descent

III. 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)

IV. 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 (often associated with mucus or pus) in Ulcerative Colitis
      1. Uncommon in Crohn Disease
  4. Associated symptoms
    1. Tenesmus
    2. Rectal urgency
    3. Constitutional symptoms (fever, weight loss, malaise)

V. 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)

VI. Associated Conditions: Extraintestinal

  1. See Gynecologic Manifestations of Crohn's Disease
  2. See Spondyloarthropathy due to Inflammatory Bowel Disease
  3. General
    1. Extraintestinal findings are associated with 25% of Inflammatory Bowel Disease cases
    2. Crohns Disease and Ulcerative Colitis are associated with similar extraintestinal disorders (more common in Crohns Disease)
  4. Musculoskeletal
    1. Osteoporosis
    2. Colitic Arthritis
    3. Ankylosing Spondylitis
  5. Ocular
    1. Episcleritis
    2. Scleritis
    3. Uveitis
    4. Recurrent Iritis
  6. Dermatologic
    1. Digital Clubbing
    2. Erythema Nodosum
    3. Pyoderma Gangrenosum
    4. Lichen Planus
    5. Aphthous Stomatitis
    6. Psoriasis
  7. Hepatobiliary
    1. Hepatic Steatosis
    2. Primary Sclerosing Cholangitis
      1. Occurs in as many as 2.5 to 7.5% of Ulcerative Colitis patients
      2. Progresses to Cirrhosis and liver failure in most patients
    3. Cholelithiasis
    4. Pericholangitis
  8. Nephrolithiasis and Ureterolithiasis
    1. Decreased bile secretion with secondary steatorrhea results in increased oxalate absorption and oxaluria
    2. Dehydration and Metabolic Acidosis further risks Kidney Stone formation
  9. Venous Thromboembolism (Deep Vein Thrombosis, Pulmonary Embolism)
    1. Relative Risk 4.3
    2. Relative Risk 15.8 during a flare (esp. hospitalization)
    3. Multifactorial pathogenesis (increased inflammation and decreased Fibrinolysis, immobilization, Dehydration, Corticosteroids)
  10. Opportunistic Infections in Immunocompromised Patients
    1. See labs below for related organisms
    2. May be due to Immunosuppressant and Biologic Agents used to treat Inflammatory Bowel Disease
    3. May also be due to inflammatory bowel conditions secondary to Immunosuppression (e.g. Chemotherapy)
    4. Biologic Agents (e.g. Infliximab) may risk Tuberculosis, fungal infections
    5. Myelosuppression (Bone Marrow suppression) may occur with Cyclosporine, 6-Mercaptopurine and Azathioprine

VII. Labs: Underlying Nutrition and Disease Severity

  1. Complete Blood Count
    1. Iron Deficiency Anemia is common
  2. Comprehensive metabolic panel
    1. Testing may also be consistent with Dehydration related to decreased oral intake
  3. C-Reactive Protein or Erythrocyte Sedimentation Rate
    1. Correlates with severity
  4. Serum Protein level
    1. Serum Albumin
    2. Serum Transferrin
    3. Serum Prealbumin
  5. Iron Indices
    1. Serum Ferritin
    2. Serum Iron
    3. Total Iron Binding Capacity

VIII. Labs: Stool Studies

  1. Infectious Diarrhea Causes (obtain in all suspected Inflammatory Bowel Disease cases and flares of known disease)
    1. Clostridium difficile Toxin and culture
    2. Enteric Pathogens Nucleic Acid Test Panels (Stool NAT)
      1. Replaces Stool Culture and includes specific Diarrheal causes (e.g. Toxigenic Escherichia coli)
  2. 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]
  3. Additional Stool studies
    1. Stool for Ova and Parasites
    2. GiardiaAntigen
    3. Yersinia enterocolitica culture
    4. Entamoeba histolytica serologic titers
    5. Fecal Leukocytes

X. 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
      4. Toxic Megacolon (accordion sign, target sign)
      5. Bowel perforation
      6. Intraabdominal abscess
      7. Fistula (Crohn Disease)
      8. Fibrosis (Crohn Disease, with homogenous bowel wall thickening)
  2. Abdominal XRay findings (if done for other reasons)
    1. Perforation signs (i.e. Free air in peritoneum)
    2. Toxic Megacolon
      1. Dilated transverse colon >6 cm (with other systemic findings)
    3. Thumb-printing
      1. Pattern of multiple locations where bowel wall appears indented (as if by a thumbs)

XI. Differential Diagnosis: General

  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

XII. 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

XIII. Diagnosis

  1. Colonoscopy with mucosal biopsy
  2. Crohn Disease often has a delayed diagnosis (mean 7 years of symptoms prior to correct diagnosis)
  3. Inflammatory Bowel Disease initial diagnosis (Crohn Disease versus Ulcerative Colitis) is incorrect >80% of the time
    1. Mitchell (2007) Tech Coloproctol 11(2): 91-6 [PubMed]

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
    4. Moderate to severe initial presentation may require hospitalization
    5. Consult general surgery for emergent conditions (e.g. Toxic Megacolon, fulminant colitis, bowel perforation, obstruction)
  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. Kleinmann (2023) Crit Dis Emerg Med 37(2): 22-9
  3. McDowell (2022) Inflammatory Bowel Disease, StatPearls, Treasure Island
    1. https://www.ncbi.nlm.nih.gov/books/NBK470312/

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