Malaise, fever, weight loss Common Common Rectal bleeding Sometimes Usual Abdominal mass Common Rare Abdominal pain Common Common Perianal disease Common Rare Ileal involvement Common None (backwash ileitis) Strictures Common Unusual Fistula Common Very rare Skip lesions Common Not present Transmural Involvement Usual Not present Crypt abscesses Variable Usual Intestinal granulomas Common Rarely present Risk of cancer* Increased Greatly increased Erythema nodosum Common Less common Mouth ulceration Common Rare Osteopenia at onset Yes No Autoimmune hepatitis Rare Yes Sclerosing cholangitis Rare Yes *Colonic cancer, cholangiocarcinoma, lymphoma in Crohn’s disease.
cases. Anti–Saccharomyces cerevisiae antibody is presentin about 50% of CD patients and is uncommon in UC. MoreIBD-specific antibodies are being developed and include anti-OmpC, directed against an Escherichia coli membrane protein, and anti-CBir1, directed against bacterial flagellin,among others. Because there is overlap between CD and UC, none of these tests can discriminate absolutely between the two conditions.
In patients with suspected IBD, an upper GI series with small bowel follow-through is often used to detect small bowel involvement. Colonoscopy is preferred over contrast enemabecause biopsy specimens can be obtained and because visualfeatures can be diagnostic. Findings in UC include diffuse carpeting of the distal or entire colon with tiny ulcers and loss of haustral folds. Within the involved segment, no skip areas arepresent. In CD, ulcerations tend to be much larger with a linear,branching, or aphthous appearance; skip areas are usually present. Upper endoscopy cannot evaluate the jejunum and ileum,but is more sensitive than contrast studies in identifying proximalCD involvement. Other methods to detect small bowel involvement include video capsule endoscopy; computed tomography (CT) scanning, which can detect small bowel disease as well as abscesses; and MR enterography, which has the advantage of noradiation and good sensitivity for finding active bowel disease.
UC is treated with the aminosalicylate drugs, which deliver 5-aminosalicylic acid (5-ASA) to the distal gut. Because it is
CBC with WBC Anemia, elevated platelets suggest IBD differential ESR Elevated in many, but not all, IBD patients C-reactive protein Elevated in many, but not all, IBD patients Albumin May be low in IBD due to fecal loss ASCA Found in about 50% of CD patients and few UC patients Atypical p-ANCA Found in most UC patients and few CD patients Anti-OmpC Found in some UC and CD patients, rare in non-IBD Anti-C Bir1 Found in about 50% of CD patients
Upper GI series with Evaluate for ileal and jejunal CD SBFT
CT scan Used to detect abscess, small bowel involvement
Tagged WBC scan Sometimes helpful in determining extent of disease
Magnetic Resonance Used to detect bowel thickening, Enterography inflammation, and strictures as well as
Upper endoscopy Evaluate for CD of esophagus, stomach, and duodenum; obtain tissue for histologic diagnosis
Colonoscopy Show presence or absence of colitis and terminal ileal CD; obtain tissue for histology
Video Capsule Emerging role in diagnosis of small bowel endoscopy CD, more sensitive than upper GI series with SBFT
Anti-OmpC, Antibody to outer membrane protein C; ASCA, anti–
Saccharomyces cerevisiae antibody; atypical p-ANCA, atypical perinuclear staining by antineutrophil cytoplasmic antibody; CBC, complete blood count; CD, Crohn’s disease; ESR, erythrocyte sedimentation rate; GI, gastrointestinal; IBD, inflammatory bowel disease; SBFT, small bowel follow- through; WBC, white blood cell.