Defecography is a technique of examining the rectum and anal canal in which the patient is studied while sitting down rather than recumbent and recordings are obtained both at rest and during straining. The authors describe their findings in 83 patients with dyschezia. Defecation was normal in 28 patients. Prolapse of the anal mucosa was seen in 13 patients and internal procidentia in 23, 12 of whom also had intussusception manifested as rectal prolapse. A deep rectogenital fossa associated with an enterocele was seen in 16 patients; 13 had a proctocele, while fecal retention was seen in 5. Descent of the pelvic floor and changes in the angle between the rectum and anal canal were assessed. The authors recommend defecography as a more physiological means of assessing rectal dysfunction.