Ulcerative colitis

Abbreviations

Introduction

In clinical practice the Montreal classification of ulcerative colitis (UC) has routinely been used to guide diagnosis and treatment ( Table 1.1 ) . In addition to the clinical assessment, the identification of endoscopic and histologic features is the key to the diagnosis and differential diagnosis of UC as well as Crohn’s disease (CD). Colonoscopy also plays a critical role in the disease monitoring, assessment of treatment response, surveillance of colitis-associated neoplasia (CAN), and endoscopic therapy . The matrix of measuring a quality colonoscopy in UC includes (1) adequate level of intubation, especially the intubation of the terminal ileum; (2) assessment of disease extent and distribution pattern; (3) grading of degree and features of mucosal inflammation; and (4) proper biopsy. Detailed information on grading the severity of mucosal inflammation in UC as well as CD is discussed in Chapter 11 , Ulcerative colitis: postsurgical and Chapter 14 , Endoscopic scores in inflammatory bowel disease. Colonoscopic features of superimposed infections are discussed in Chapter 23 , Superimposed infections in inflammatory bowel diseases.

Adequate bowel preparation is needed for a quality colonoscopy in UC. Active mucosal inflammation often presents with mucopurulent or fibrin exudates or plaques, which should be washed to evaluate true pattern and severity of mucosal inflammation ( Fig. 9.1 ).

Disease extent and distribution

Patients with chronic diarrhea (i.e., the symptom lasting more than 4 months) should have colonoscopy evaluation for noninfectious etiologies, including inflammatory bowel disease (IBD) and microscopic colitis. The assessment on index colonoscopyprior to medical therapy more accurately reflects true disease extent . The classic UC at initial presentation demonstrates continuous inflammation extending proximally from the anal verge and rectum.