Inflammatory Bowel Disease

Aka: Inflammatory Bowel Disease, Autoimmune Bowel Disorder

1. See Also
   1. Chronic Diarrhea
2. Epidemiology
   1. Age: 10 to 40 years old
   2. First degree relative with Inflammatory Bowel Disease increases risk 10 fold
3. 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
4. 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)
5. 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
6. 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)
7. 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
8. Labs: Immunocompromised Patient Evaluation
   1. Chlamydia trachomatis
   2. CryptosporidiumAntigen
   3. Neisseria gonorrhoeae
   4. Herpes Simplex Virus (HSV)
   5. Cytomegalovirus (CMV)
   6. Isospora belli
   7. Mycobacterium tuberculosis
9. Labs: Underlying Nutrition and Disease Severity
   1. C-Reactive Protein or Erythrocyte Sedimentation Rate
      1. Correlates with severity
   2. Serum Protein level
      1. Serum Albumin
      2. Serum Transferrin
      3. Serum Prealbumin
   3. Hemoglobin
10. Differential Diagnosis: Distinguishing Crohn's Disease from Ulcerative Colitis
    1. Location
       1. Crohn's Disease can involve any area of Gastrointestinal Tract
       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. Rectal Bleeding is more common in Ulcerative Colitis
       4. Colon Cancer is much more common in Ulcerative Colitis
11. Diagnosis
    1. Colonoscopy with mucosal biopsy
12. Imaging
    1. CT Abdomen and Pelvis (or MRI Abdomen)
    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)
13. 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