II. Epidemiology
- Age: 10 to 40 years old
- First degree relative with Inflammatory Bowel Disease increases risk 10 fold
III. Differential Diagnosis
-
Lower GI Bleeding
- Diverticulitis (most common cause)
- Angiodysplasia (Arteriovenous Malformation)
- Neoplasm
- Ulcerative Colitis (Blood Diarrhea distinguishes from Crohn's Disease)
- Ischemic Colitis (Older patients with sudden onset pain)
- Anorectal Disease
-
Diarrhea
- Non-Infectious Osmotic Diarrhea
- Non-Infectious Secretory Diarrhea
- Ulcerative Colitis (bloody Diarrhea)
- Crohn's Disease
- Irritable Bowel Syndrome (diagnosis of exclusion)
- Fecal Impaction (with leakage)
- Infectious Diarrhea (Sudden onset and often painful)
IV. History
- Travel
- Contaminated intake
- Immunodeficiency risk
- High risk sexual behavior
- Family History of Gastrointestinal disease
- Medications in the last 6 months (e.g. antibiotics)
V. Symptoms
-
Chronic Inflammatory Diarrhea
- Crohn Disease may also cause Secretory Diarrhea (Chronic Watery Diarrhea)
- Pain
- Ulcerative Colitis
- Lower abdominal cramps
- Relieved with Bowel Movement
- Crohn's Disease
- Constant pain often in right lower quadrant
- Not relieved with Bowel Movement
- Ulcerative Colitis
-
Stool Blood
- Grossly bloody stool in Ulcerative Colitis
VI. Signs
- Abdominal Mass
- Ulcerative Colitis: No abdominal mass
- Crohn's Disease: Mass often at Right lower quadrant
-
Gastrointestinal Tract Affected
- Ulcerative Colitis
- Affects only colon
- Continuous from Rectum
- Crohn's Disease
- Mouth to anus potentially affected
- Discontinuous, "Skip" lesions
- Ulcerative Colitis
-
Bowel Tissue affected
- Ulcerative Colitis: Mucosal disease (no Granuloma)
- Crohn's Disease: Transmural disease (Granulomas)
VII. Associated Conditions: Extraintestinal
- See Gynecologic Manifestations of Crohn's Disease
- See Spondyloarthropathy due to Inflammatory Bowel Disease
- Crohns Disease and Ulcerative Colitis are associated with similar extraintestinal disorders (more common in Crohns Disease)
- Musculoskeletal (Osteoporosis, Colitic Arthritis, Ankylosing Spondylitis)
- Ocular (Episcleritis, Uveitis, Recurrent Iritis)
- Dermatologic (Digital Clubbing, Erythema Nodosum, Pyoderma Gangrenosum, Lichen Planus, Aphthous Stomatitis, Psoriasis)
- Hepatobiliary (Hepatic Steatosis, Primary Sclerosing Cholangitis, Cholelithiasis, Pericholangitis)
- Nephrolithiasis
- Hypercoagulable state (Deep Vein Thrombosis, Pulmonary Embolism)
VIII. Labs: Stool Studies
-
Fecal Calprotectin
- Newer test with high Test Sensitivity and Test Specificity for Inflammatory Bowel Disease
- Fecal Calprotectin <40 mcg/g and CRP <0.5 reduce Inflammatory Bowel Disease likelihood to<1%
- General Stool studies
- Additional Stool studies
- Yersinia enterocolitica culture
- Toxigenic Escherichia coli isolation
- Entamoeba histolytica serologic titers
IX. Labs: Immunocompromised Patient Evaluation
X. Labs: Underlying Nutrition and Disease Severity
- Complete Blood Count
-
C-Reactive Protein or Erythrocyte Sedimentation Rate
- Correlates with severity
- Serum Protein level
- Iron Indices
XI. Differential Diagnosis: Distinguishing Crohn's Disease from Ulcerative Colitis
- Location
- Crohn's Disease can involve any area of Gastrointestinal Tract (most common in ileocolic region)
- Ulcerative Colitis is typically limited to colon, and has onset at the Rectum
- Thickness
- Crohn's Disease involves the entire bowel wall
- Ulcerative Colitis is limited to the mucosa and submucosa
-
Colonoscopy
- Crohn's Disease demonstrates skip lesions, cobblestoning, ulcerations and strictures
- Ulcerative Colitis demonstrates pseudopolyps, continuous areas of inflammation
- Other discriminating factors
- Anemia is more common in Ulcerative Colitis
- Abdominal Pain is more common in Crohn's Disease
- Anorexia and weight loss is common in Crohn's Disease
- Rectal Bleeding is more common in Ulcerative Colitis (bloody Diarrhea is a common presentation)
- Colon Cancer is much more common in Ulcerative Colitis
XII. Diagnosis
- Colonoscopy with mucosal biopsy
XIII. Imaging
-
CT Abdomen and Pelvis (or MRI Abdomen)
- Undifferentiated Inflammatory Bowel Disease (prior to diagnosis)
- Known Inflammatory Bowel Disease with complication
- Small Bowel Obstruction
- Sepsis with suspected intraabdominal source
- Perianal Sepsis
- Abdominal XRay findings (if done for other reasons)
- Perforation signs (i.e. Free air in peritoneum)
- Toxic Megacolon
- Thumb-printing
- Pattern of multiple locations where bowel wall appears indented (as if by a thumbs)
XIV. Management
- See Ulcerative Colitis (bloody Diarrhea)
- See Crohn's Disease
- See Microscopic Colitis
- Precautions
- Consult gastroenterology in acute presentations prior to diagnosis and in exacerbations
- Avoid management (e.g. Corticosteroids) that interfere with diagnosis prior to definitive study (e.g. Colonoscopy)
- Exclude infection (e.g. C. difficile and other enteric Bacterial Infection) pre-diagnosis and with exacerbations
- Symptom management in formally diagnosed Inflammatory Bowel Disease (e.g. prior Colonoscopy with biopsy)
- Avoid starting Corticosteroids unless infection has been excluded, IBD cause is known and GI consultant agrees
- Ongoing Inflammatory Bowel Disease management may be adjusted
- Patients with increased symptoms on a Corticosteroid taper could return to the prior dose
- Patients on 5-Aminosalicylic Acid could have dosing maximized or add rectal enema (4 g)
XV. Resources
- Crohn's and Colitis Foundation of America
- Cedars-Sinai Inflammatory Bowel Disease Center
XVI. References
- Cardy and Williams in Swadron (2022) EM:Rap 22(7): 15-7
- McDowell (2022) Inflammatory Bowel Disease, StatPearls, Treasure Island