Difference Between Crohn's disease and Ulcerative Colitis

Crohn's Disease and Ulcerative Colitis are both forms of Inflammatory Bowel Disease (IBD).

Important points regarding Crohn disease
p-ANCA is positive in 11% of cases;anti-Saccharomyces cere-
visiae antibody is common (rare in ulcerative colitis).
Approximately 30–50% concordance among monozygotic
twins.

Clinical presentation of Crohn disease
■ Symptoms: Diarrhea,abdominal pain,weight loss,and fever;
bloody diarrhea; also associated with psychiatric symptoms.
■ Diagnosis: Colonoscopy reveals longitudinal ulcerations and
cobblestoning; granulomas may be present on biopsy (50%).
“String sign” on barium contrast studies. “Creeping fat” on
CT scan

Crohn disease. A, Note the transmural nature of the
inflammatory infiltrate. Within the muscularis propria and submu-
cosa is a large cluster of lymphocytes associated with multiple
granulomas. B, A high-power view of one of the granulomas.
Hematoxylin and eosin,


Clinical presentation of Ulcerative Colitis
■ Symptoms: Profuse watery diarrhea with blood, mucus, and
pus; abdominal pain; and hematochezia (bright red blood
per rectum). Pyoderma gangrenosum initially presents simi-
lar to cellulitis but fails to respond to antibiotics; typically
causes deep ulceration with a violaceous border.
■ Diagnosis: Barium enema shows loss of haustra;colonoscopy
with biopsy.

Ulcerative colitis. A and B, The mucosal nature of the
inflammatory infiltrate and the near complete loss of mucosa. The
residual mucosa is polypoid in appearance, but only because of
the loss of the surrounding mucosa; hence, the designation of
“pseudopolyp.” B, The arrowhead indicates the loss of mucosa,
and the arrow indicates a pseudopolyp. Hematoxylin and eosin.