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Essentials of Diagnosis
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Insidious onset
Intermittent bouts of low-grade fever, diarrhea, and right lower quadrant pain
Right lower quadrant mass and tenderness
Perianal disease with fistulas, fissures, and abscesses
Radiographic or endoscopic evidence of ulceration, stricturing, or fistulas of the small intestine or colon
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General Considerations
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Crohn disease is a transmural process
Crohn disease may involve
Small bowel only, most commonly the terminal ileum (ileitis) in ~33% of cases
Small bowel and colon, most often the terminal ileum and adjacent proximal ascending colon (ileocolitis) in ~50%
Colon alone in 20%
Chronic illness with exacerbations and remissions
One-third of patients have associated perianal disease (fistulas, fissures, abscesses)
Less than 5% of patients have symptomatic involvement of the upper intestinal tract
Smokers are at increased risk
Treatment is directed both toward improving the symptoms and controlling the disease process
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Chronic inflammatory disease
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Malaise, loss of energy
Diarrhea, nonbloody, intermittent
Cramping or steady right lower quadrant or periumbilical pain
Focal tenderness, right lower quadrant
Palpable, tender mass in the lower abdomen
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Intestinal obstruction
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Postprandial bloating, cramping pains, and loud borborygmi
Narrowing of the small bowel may occur as a result of inflammation, spasm, or fibrotic stenosis
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Fistulization with or without infection
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Sinus tracts and fistulas can result in intra-abdominal or retroperitoneal abscesses manifested by fevers, chills, tender abdominal mass, and leukocytosis
Fistulas can occur
Between the small intestine and the colon and commonly are asymptomatic but can cause
Diarrhea
Weight loss
Bacterial overgrowth
Malnutrition
Between the small intestine and the bladder or vagina and can cause
Between the small intestine and the skin and can cause
Cutaneous fistulas
Perianal abscesses
Anal fissures
Skin tags
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Extraintestinal manifestations
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Differential Diagnosis
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Ulcerative colitis
Irritable bowel syndrome
Appendicitis
Yersinia enterocolitica enteritis
Mesenteric adenitis
Intestinal lymphoma
Segmental colitis due to ischemic colitis, tuberculosis, amebiasis, chlamydia
Diverticulitis or appendicitis with abscess
Nonsteroidal anti-inflammatory drug–induced colitis
Perianal fistula due to other cause
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