Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + • Diarrhea• Abdominal pain and palpable mass• Low-grade fever, lassitude, weight loss• Anemia• Radiographic findings of thickened, stenotic bowel with ulceration and internal fistulas +++ Epidemiology + • A chronic progressive granulomatous inflammatory disorder affecting any part of the GI tract• From 2 to 9 cases per 100,000 are detected annually in the United States• Geographic variation (more common in urban dwellers and Northern residents of the United States), and there is a relatively high incidence among Ashkenazi Jews• Peak incidence between the second and fourth decades• The cause is unknown; appears to result from the interaction of genetic and environmental factors.• The distal ileum is the most frequent site of involvement, eventually becoming diseased in 75% of cases• Small bowel alone is involved in 15-30%, both the distal ileum and the colon in 40-60%, duodenum in 0.5-7%. +++ Symptoms and Signs + • Diarrhea: Characteristically contains no blood if small bowel alone is diseased• Acute and recurrent abdominal pain• Malaise• Weight loss• Malnutrition• Fever• Palpable abdominal mass• Abdominal tenderness• Anorectal lesions: Chronic anal fissures, large ulcers, complex anal fistulas, or pararectal abscesses +++ Laboratory Findings + • Iron deficiency or macrocytic anemia due to vitamin B12 or folate deficiency• Elevated ESR• Hypoalbuminemia• Abnormal d-xylose absorption suggests extensive disease or fistula formation, since carbohydrate is normally absorbed in the jejunum. +++ Imaging Findings + • Upper GI contrast radiography-Thickened bowel wall with stricture-Longitudinal ulceration-Deep transverse fissures and cobblestone formation-Fistulas and abscesses may also be detected• GI endoscopy-Mucosal lesions of affected areas appear grossly as tiny hemorrhagic spots or shallow ulcers-Skip areas appear normal-Fissures serpiginous or linear ulcers surrounding islands of intact mucosa overlying edematous submucosa give a cobblestone appearance to the luminal surface-Stricture formation + • Systemic manifestations include:-Hepatobiliary disease-Uveitis-Arthritis-Ankylosing spondylitis-Aphthous ulcers-Erythema nodosum-Amyloidosis-Thromboembolism-Vascular disorders-Cutaneous ulcers with a granulomatous reaction• About 70% of patients with Crohn disease undergo a definitive operation• If multiple strictures are encountered, they can be treated by "strictureplasty," in which the bowel is incised through the stricture and the wall is sutured or stapled so that the lumen is widened. +++ Rule Out + • Ulcerative colitis• Appendicitis• TB• Lymphoma• Carcinoma• Amebiasis• Ischemia• Eosinophilic gastroenteritis + • Upper GI contrast radiography• Upper GI endoscopy +++ When to Admit + • Acute exacerbations• Obstruction• Perforation• Abscess +++ When to Refer + • Most cases of Crohn disease of the small bowel should be managed in conjunction with a gastroenterologist + • Surgery should ... Your Access profile is currently affiliated with [InstitutionA] and is in the process of switching affiliations to [InstitutionB]. Please select how you would like to proceed. Keep the current affiliation with [InstitutionA] and continue with the Access profile sign in process Switch affiliation to [InstitutionB] and continue with the Access profile sign in process Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Error: Incorrect UserName or Password Username Error: Please enter User Name Password Error: Please enter Password Sign in Forgot Password? Forgot Username? Download the Access App: iOS | Android Sign in via OpenAthens Sign in via Shibboleth You already have access! Please proceed to your institution's subscription. Create a free profile for additional features.