Inflammatory bowel disease, an umbrella term used for Crohn disease and ulcerative colitis, is often accompanied with the presenting symptom of diarrhea. This symptom can be a great nuisance and emotionally distressing to the individual with inflammatory bowel disease. Although the exact etiology of inflammatory bowel disease is still unknown, interactions between the host susceptibility, mucosal immunity, and intestinal microflora are thought to be major factors. One intervention that is gaining increasing support by the research and medical community is the use of probiotics, which work on the intestinal flora by altering the bacterial composition and thereby rendering the environment unfavorable to pathogenic organisms. The human response to illness model provides an ideal organizing framework to gain a comprehensive understanding of the human response of diarrhea in the inflammatory bowel disease population. By examining the physiological, pathophysiological, behavioral, and experiential perspectives as well as individual vulnerabilities, this model establishes sound rationale to guide nursing interventions to help the individual better cope with the physical and emotional effects of having diarrhea. This model also facilitates the provision of holistic and personalized care, which may include the use of probiotics to help alleviate this distressing symptom.