ABSTRACT
This chapter examines the various organic and functional etiologies of fecal incontinence caused by chronic radiation bowel injury. Radiotherapy is being used increasingly for the treatment of malignancy arising in the pelvic viscera. The incidence of associated radiation injury to surrounding healthy tissue with its sequelae has increased as increasing field sizes are employed in an attempt to improve cure rates. A common symptom of radiation rectal injury is urgency and increased frequency of defecation with varying degrees of fecal incontinence. Radiological studies and examination under anesthesia with endoscopy are necessary to define the various fistulas. J. S. Varma studied rectal function manometrically in patients with mild or moderate symptomatic chronic radiation rectal injury and compared it to a matched control group of asymptomatic subjects. The marked damage to the myenteric plexus seen histologically may be responsible for the abnormalities of distensibility or nonrelaxation, as suggested by absence or reduction in amplitude of the rectal distension reflex in such patients.
