II. Epidemiology
- Age: 10 to 40 years old
- Prevalence of Inflammatory Bowel Disease: 3.1 Million in U.S.
- First degree relative with Inflammatory Bowel Disease increases risk 10 fold
- More common in caucasian patients
- More common in Ashkenazi Jewish descent
III. History
- Travel
- Contaminated intake
- Immunodeficiency risk
- High risk sexual behavior
- Family History of Gastrointestinal disease
- Medications in the last 6 months (e.g. Antibiotics)
IV. 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 (often associated with mucus or pus) in Ulcerative Colitis
- Uncommon in Crohn Disease
- Grossly bloody stool (often associated with mucus or pus) in Ulcerative Colitis
- Associated symptoms
- Tenesmus
- Rectal urgency
- Constitutional symptoms (fever, weight loss, malaise)
V. 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)
VI. Associated Conditions: Extraintestinal
- See Gynecologic Manifestations of Crohn's Disease
- See Spondyloarthropathy due to Inflammatory Bowel Disease
-
General
- Extraintestinal findings are associated with 25% of Inflammatory Bowel Disease cases
- Crohns Disease and Ulcerative Colitis are associated with similar extraintestinal disorders (more common in Crohns Disease)
- Musculoskeletal
- Ocular
- Episcleritis
- Scleritis
- Uveitis
- Recurrent Iritis
- Dermatologic
- Hepatobiliary
- Hepatic Steatosis
- Primary Sclerosing Cholangitis
- Occurs in as many as 2.5 to 7.5% of Ulcerative Colitis patients
- Progresses to Cirrhosis and liver failure in most patients
- Cholelithiasis
- Pericholangitis
-
Nephrolithiasis and Ureterolithiasis
- Decreased bile secretion with secondary steatorrhea results in increased oxalate absorption and oxaluria
- Dehydration and Metabolic Acidosis further risks Kidney Stone formation
-
Venous Thromboembolism (Deep Vein Thrombosis, Pulmonary Embolism)
- Relative Risk 4.3
- Relative Risk 15.8 during a flare (esp. hospitalization)
- Multifactorial pathogenesis (increased inflammation and decreased Fibrinolysis, immobilization, Dehydration, Corticosteroids)
- Opportunistic Infections in Immunocompromised Patients
- See labs below for related organisms
- May be due to Immunosuppressant and Biologic Agents used to treat Inflammatory Bowel Disease
- May also be due to inflammatory bowel conditions secondary to Immunosuppression (e.g. Chemotherapy)
- Biologic Agents (e.g. Infliximab) may risk Tuberculosis, fungal infections
- Myelosuppression (Bone Marrow suppression) may occur with Cyclosporine, 6-Mercaptopurine and Azathioprine
VII. Labs: Underlying Nutrition and Disease Severity
-
Complete Blood Count
- Iron Deficiency Anemia is common
- Comprehensive metabolic panel
- Testing may also be consistent with Dehydration related to decreased oral intake
-
C-Reactive Protein or Erythrocyte Sedimentation Rate
- Correlates with severity
- Serum Protein level
- Iron Indices
VIII. Labs: Stool Studies
-
Infectious Diarrhea Causes (obtain in all suspected Inflammatory Bowel Disease cases and flares of known disease)
- Clostridium difficile Toxin and culture
- Enteric Pathogens Nucleic Acid Test Panels (Stool NAT)
- Replaces Stool Culture and includes specific Diarrheal causes (e.g. Toxigenic Escherichia coli)
-
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%
- Additional Stool studies
- Stool for Ova and Parasites
- GiardiaAntigen
- Yersinia enterocolitica culture
- Entamoeba histolytica serologic titers
- Fecal Leukocytes
IX. Labs: Immunocompromised Patient Evaluation
X. 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
- Toxic Megacolon (accordion sign, target sign)
- Bowel perforation
- Intraabdominal abscess
- Fistula (Crohn Disease)
- Fibrosis (Crohn Disease, with homogenous bowel wall thickening)
- Abdominal XRay findings (if done for other reasons)
- Perforation signs (i.e. Free air in peritoneum)
- Toxic Megacolon
- Dilated transverse colon >6 cm (with other systemic findings)
- Thumb-printing
- Pattern of multiple locations where bowel wall appears indented (as if by a thumbs)
XI. Differential Diagnosis: General
-
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)
XII. 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
XIII. Diagnosis
- Colonoscopy with mucosal biopsy
- Crohn Disease often has a delayed diagnosis (mean 7 years of symptoms prior to correct diagnosis)
- Inflammatory Bowel Disease initial diagnosis (Crohn Disease versus Ulcerative Colitis) is incorrect >80% of the time
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
- Moderate to severe initial presentation may require hospitalization
- Consult general surgery for emergent conditions (e.g. Toxic Megacolon, fulminant colitis, bowel perforation, obstruction)
- 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
- Kleinmann (2023) Crit Dis Emerg Med 37(2): 22-9
- McDowell (2022) Inflammatory Bowel Disease, StatPearls, Treasure Island