Ulcerative colitis (UC) is a chronic relapsing and remitting intestinal disorder plagued by diffuse and continuous mucosal inflammation involving the rectum, and extending proximally throughout the colon. As one of two well-known disease types grouped under the umbrella of inflammatory bowel diseases (IBDs), the inflammatory hallmark in UC is limited to the mucosa. The etiology of UC is not yet completely understood; however, research over the last several decades has led to a better understanding of cellular, immunological, and molecular mechanisms involved in its pathogenesis. Scientists continue to discover new and innovative approaches in the development of potential biomarkers, diagnostic tools, and treatment options for patients with this disease. In this chapter, the authors present a broad overview of disease epidemiology, presentation and diagnosis, and current options for medical management with a focus on the surgical approaches to treatment of UC.
Over 1.5 million Americans and 2.2 million Europeans are currently estimated to be afflicted with UC.1 The incidence of UC in the United States and Northern Europe is 9 to 20 cases per 100,000 patients per year.2 Its prevalence ranges from 156 to 291 cases per 100,000 people.2 UC is less common in Eastern and Southern European countries, specifically among Asian, Hispanic, and African American populations. Ashkenazi Jews have demonstrated some of the highest frequencies of UC, estimated at 3 to 5 times higher than other ethnic groups.2 No significant gender discrepancy has been documented. Disease onset is not targeted to a specific age group and may present at any time. However, the age of onset is bimodal in distribution, wherein the primary peak is typically 15 to 30 years and a second, smaller peak occurs in the sixth to seventh decade of life.
Although the exact pathophysiology of UC remains unknown, it is postulated to be the result of a combination of dysregulated interactions between the host’s genetic predisposition, environmental triggers and exposures, and the intestinal microbiome, all of which undoubtedly interact with the innate and adaptive immune systems. The overarching hypotheses suggest that the above-mentioned factors function dependently on one another to establish and maintain intestinal homeostasis, which is altered upon dysregulation of any of the contributing players, presenting a platform upon which UC can develop.
Studies in molecular genetics have shed light onto the genetic contribution to the development of UC. Monozygotic twin studies have demonstrated concordance rates of 16% in UC.3 In addition, 8% to 14% of patients with UC were found with a family history of IBD, and a first-degree family member with UC statistically increases a person’s risk of development of IBD by approximately tenfold.3,4 To date, genome-wide association studies have identified 163 loci linked to IBD.3 Although disease-specific genes have not yet been identified, patients with UC are often found with mutations of ...