Crohn’s disease primarily affects young adults. This chronic, complex, idiopathic inflammatory bowel disease often occurs within families and is more common in Jewish persons.
The long-term management of Crohn’s disease is a team effort. The involvement of a gastroenterologist is essential because the treatment options are complex and continually evolving. Encourage patients and their families to learn about the disease; the Crohn’s and Colitis Foundation of America (www.ccfa.org) and similar organizations offer information and support.
In a previous article (CONSULTANT, April 1, 2001, page 541), I focused on ulcerative colitis, which can be distinguished from Crohn’s disease by anatomic distribution and histopathology (Table). Here I discuss the findings that govern the choice of therapy for Crohn’s disease and weigh the pros and cons of the various management options.
Disease location and activity. The prognosis and response to therapy are based on the site of involvement and the behavior of the disease.1 Crohn’s disease can involve any part of the digestive tract—from the mouth to the anus. In about 40% of patients, the terminal ileum (Figure 1) and cecum are affected; 30% have isolated small-bowel disease; 25% have isolated colonic disease (Figure 2); and 5% have esophageal, gastric, or duodenal involvement.2 Colonic involvement may be patchy or continuous from the rectum; the latter presentation may be difficult to distinguish from ulcerative colitis.
Crohn’s disease manifests in one of the following patterns, which are based on the clinical presentation and the results of endoscopic, pathologic, and radiologic examinations:
- Nonstricturing, nonpenetrating disease that causes inflammation of the lining of the bowel and results in diarrhea and rectal bleeding; temporary obstructive narrowing of either the small or the large bowel may occur.
- Penetrating (fistulizing or perforating) disease, which features intra-abdominal, enterocutaneous, or perianal fistulas or abscesses.
- Stricturing disease that is characterized by constant luminal narrowing or stenosis, which results in obstructive signs or symptoms.3
Presenting symptoms. The clinical presentation suggests both the location and the behavior of the disease, which may vary during the course of the illness. The classic presentation—fever, diarrhea, abdominal pain, and a palpable right lower quadrant mass—usually suggests terminal ileal disease. Persistent diarrhea and rectal bleeding in an older patient might indicate Crohn’s colitis. A high fever, perianal abscess, new urinary tract infection or pneumaturia, feculent vaginal discharge, or purulent drainage from the skin suggests penetrating or fistulizing disease. Repeated episodes of intestinal obstruction point to fibrostenotic disease.
Disease severity. Several indices of disease severity are used in clinical studies, but they are difficult to apply in practice. I classify my patients’ disease activity as follows:
- Mild disease causes no systemic symptoms, such as fever, weight loss, and hypotension. The patient is ambulatory and may have mild diarrhea, rectal bleeding, or abdominal pain. Mild disease can be managed with the first-line agents described below.
- Moderate disease is characterized by more severe symptoms, including lowgrade fever and weight loss. Although some patients do not respond to oral agents and require more aggressive therapy because of worsening diarrhea, bleeding, or pain, most can be treated as outpatients.
- Severe disease usually is seen in patients in whom oral therapy has failed. Severe diarrhea; rectal bleeding; and bowel obstruction, perforation, or fistulas that require hospitalization are hallmarks of severe disease.