Factors influencing the relapse of patients with inflammatory bowel disease.

The management of relapse of inflammatory bowel disease (IBD) remains a clinical challenge and a relatively neglected area of current research. Many factors contribute to relapse, and the proper identification of the cause of each case may influence optimal management. Often, relapse is related to the failure of maintenance therapy. Mesalamine sensitivity is difficult to recognize and should be considered when increased doses are associated with the worsening of symptoms. An increase in eosinophil activity could explain seasonal relapses of IBD as a result of exposure to allergens, but other eosinophil activation pathways also will influence the course of IBD. Infection, either enteric or systemic, may trigger a relapse by activating the gastrointestinal mucosal immune system. Nonsteroidal anti-inflammatory drug use is a well-recognized cause of exacerbation of disease. Smoking status is emerging as a complex factor in IBD, and a change in smoking status may influence the course of IBD.