ABSTRACT
The linkage between opioids and gastrointestinal function has a long history, beginning with the use of opium to treat dysentery or other digestive system disorders in ancient Greece and Asia Minor, described by Archigenes (Beneditti and Permuda, 1990). Therapeutic use of opium to treat diarrheal diseases became widespread in Europe during the Middle Ages. The mechanism of the antidiarrheal effect of opium was unknown until recently, but Felice Fontanana in the eighteenth century speculated that opium abolished intestinal irritability, and William Cullen at about the same time suggested that opium acted by decreasing spastic crisis in the intestine (Beneditti and Premuda, 1990). The use of opium increased in England in the nineteenth century, especially for treatment of diarrhea. Detailed studies of opioid actions on gastrointestinal functions, however, did not take place until the twentieth century. Several comprehensive reviews of opioid effects on gastrointestinal function have appeared (Krueger, 1937; Kosterlitz and Lees, 1964; Burks, 1975; Kromer, 1988). The discovery, in 1975, of endogenous opioid peptides (Hughes, 1975; Hughes et al., 1975) led eventually to important new insights into the gastrointestinal pharmacology of opioids.
