Evacuation disorder (ED) is defined as the inability to adequately and comfortably evacuate stool from the rectum, even when the stool is soft. It presents symptoms such as difficulty in defecation and a sensation of incomplete evacuation. ED is classified into functional ED, such as pelvic floor incoordination, and structural ED, such as rectocele and rectal intussusception. ED is common, accounting for 41% of chronic constipation with a prevalence of approximately 1.4% in the general population in Japan. Defecography is the most useful tool for diagnosing and distinguishing between functional and structural ED. However, rectocele and rectal intussusception are frequently observed on defecography even in asymptomatic individuals. Therefore, the presence of these findings in patients with defecatory symptoms does not necessarily indicate that they are the cause of the symptoms, and careful clinical correlation is required. Defecography is also valuable for accurately identifying patients with obsessive-compulsive defecation disorder who do not actually have constipation. Treatment options include bowel habit trainingBowel habit training, laxatives, suppositories, and enemas, which may provide some benefit. However, biofeedback therapyBiofeedback therapy is the most effective treatment for functional ED. For structural ED, surgical interventions, such as rectocele repair or ventral rectopexy, may be effective in carefully selected patients.