Crohn’s Disease – DIFFERENTIAL DIAGNOSIS

Patients with irritable bowel syndrome rarely present with “inflammatory” features. Persistent symptoms despite therapy for presumed irritable bowel syndrome (especially in the presence of weight loss), bleeding attributed to “hemorrhoids,” or a family history of IBD deserve a more comprehensive evaluation to exclude IBD. Most enteric infections are self-limited. Viral gastroenteritis typically lasts 1 to 4 days without rectal bleeding or fecal leukocytes. Most bacterial pathogens produce self-limited disease lasting less than 7 to 14 days, despite intermittent rectal bleeding, fevers, fecal leukocytes, and a mucosal appearance that may be indistinguishable from that of UC or CD. Occasionally, Campylobacter jejuni produces protracted symptoms and Clostridium C. difficile toxin-induced colitis can mimic the symptoms, signs, and endoscopic appearance of UC or CD. When a patient with IBD presents with new or exacerbated symptoms, stool cultures for enteric pathogens and studies for C. difficile toxin should be obtained, especially if the patient has been recently treated with antibiotics. In Northern Europe and Canada, Yersinia enterocolitica infection can mimic terminal ileitis. If the clinical suspicion warrants, cultures and serologic studies for Yersinia should be obtained. Similarly, tuberculosis of the gastrointestinal tract may mimic CD in geographic areas where intestinal tuberculosis is edemic, and, rarely, Actinomycosis simulates fistulizing CD.

Read the rest of this entry »

Crohn’s Disease – DIAGNOSIS

There are no pathognomonic clinical, endoscopic, or histologic features of the idiopathic IBD’s. The physician must therefore consider the entire clinical picture and the evolution of the illness. It is particularly important to exclude other disorders that may mimic the broad range of IBD symptoms and findings. First it is important to establish the presence of intestinal inflammation. A cardinal feature is the exudation of inflammatory cells into the lumen, manifested by fecal leukocytes or red blood cells on stool examination. Symptoms of rectal bleeding, tenesmus associated with the passage of pus, nocturnal pain and diarrhea, fever, night sweats, weight loss, or extraintestinal symptoms or signs generally exclude an uncomplicated “irritable bowel syndrome.” The presence of anemia, electrolyte disorders, hypoalbuminemia, or an elevated erythrocyte sedimentation rate of C-reactive protein is sufficient, but not necessary, to suggest IBD. On physical examination, evidence of significant weight loss or extraintestinal signs, a palpable abdominal mass or tenderness, or significant perianal disease suggests IBD. When suspicion of the diagnosis warrants, endoscopic and radiographic studies, in conjunction with histologic interpretation of biopsy specimens, confirm the diagnosis; the degree of illness at presentation should determine the aggressiveness of the diagnostic workup. Acutely ill patients should be stabilized before invasive studies are pursued.