Inflammatory bowel disease among the elderly is common, with growing incident and prevalence rates. Compared with younger IBD patients, genetics contribute less to the pathogenesis of older-onset IBD, with dysbiosis and dysregulation of the immune system playing a more significant role. Diagnosis may be difficult in older individuals, as multiple other common diseases can mimic IBD in this population. The clinical manifestations in older-onset IBD are distinct, and patients tend to have less of a disease trajectory. Despite multiple effective medical and surgical treatment strategies for adults with Crohn's disease and ulcerative colitis, efficacy studies typically have excluded older subjects. A rapidly ageing population and increasing rates of Crohn's and ulcerative colitis make the paucity of data in older adults with IBD an increasingly important clinical issue.