The clinical entities ulcerative colitis (UC) and Crohn’s disease, the former with a predilection for rectum and colon, the latter for the ileocecal region and other bowel sections, are traditionally combined under the term infl ammatory bowel diseases.
Indications: Suspicion of and differentiation between inflammatory bowel diseases.
The clinical entities ulcerative colitis (UC) and Crohn’s disease, the former with a predilection for rectum and colon, the latter for the ileocecal region and other bowel sections, are traditionally combined under the term inflammatory bowel diseases. IgA antibodies against Saccharomyces cerevisiae (ASCA), occur in 60-75% of patients with Crohn’s disease but are rare in patients with ulcerative colitis. Patients with UC have ANCA of the so-called P-ANCA type (also called atypical ANCA) in 40-50%. The combination of ASCA and ANCA is therefore used to distinguish UC from Crohn’s disease, as a typical UC patient has ANCA whereas a typical Crohn’s disease patient has ASCA. The typical onset of ulcerative colitis occurs in rectum and propagates upwards in colon and engages the mucous membrane inflammatorily with ulcerations and bloody diarrhea as a result. A number of extraintestinal manifestations (sacroiliitis, uveitis, pyodermitis, erythema nodosum and sclerosing cholangitis) also occur.
Crohn’s disease is characterized pathologically anatomically by segmental extension and more profound inflammatory changes, comprising both the mucous membrane and the intestinal wall with granuloma formation, perforations and fistula formation in the surrounding tissues as a result. Diarrhea and abdominal pains are typical and can be followed by arthritis, uveitis, sclerosing cholangitis and cobalamine deficiency (in case of ileocecal engagement). The diagnosis is mainly based on the findings of sigmoideoscopy and coloscopy and what is found in biopsies from inflamed intestinal mucous membrane. Contrast radiography of the small intestine is also valuable. Fulminant ulcerative colitis (pancolitis, toxic mega colon) is usually preceded by bloody diarrhea but clinically it can resemble angry infectious and toxic colitis and acute diverticulitis and the intestinal involvement in acute systemic vasculitis, above all WG and polyartheritisnodosa (PAN). In WG necrotising small vessel vasculites dominate but also larger blood vessels are involved and when local multiple aneurysms develop that are detectable in contrast radiography, PAN can be suspected. In order to ensure the diagnosis and follow-up in case of less acute forms of proctitis, colitis and suspected Crohn’s disease and of intestinal diseases with anatypical distribution and course, a referral to a gastroenterological unit with endoscopic competence and experience is recommended.