There is no doubt that ayahuasca makes you vomit. There is some consolation in the fact that the vomiting will ease with continued experience; shamans seldom vomit. There is more consolation in the fact that the vomiting is considered to be cleansing and healing. But the vomiting is certainly distressing to a gringo, who has been taught that vomiting is wretched and humiliating. Indeed, ayahuasca vomiting has become something of a literary trope. Poet Allen Ginsberg has described the physical part of his ayahuasca experiences. “Stomach vomiting out the soul-vine,” he writes, “cadaver on the floor of a bamboo hut, body-meat crawling toward its fate.” William S. Burroughs writes: “I must have vomited six times. I was on all fours convulsed with spasms of nausea. I could hear retching and groaning as if I was some one else.” Novelist Alice Walker speaks of the effect of ayahuasca on her protagonist — horrible-tasting medicine, gut-wrenching nausea and diarrhea, “waves of nausea … like real waves, bending her double by their force.”

Anthropologist Michael Taussig, investigating the shamanism of the Colombian Putumayo, felt compelled to drink ayahuasca — he uses the Colombian term yagé — as part of his research. “Somewhere,” he writes, “you have to take the bit between your teeth and depict yagé nights in terms of your own experience.” And one gets the ineluctable impression that Taussig hated the experience of drinking ayahuasca, hated the corporeality of its effects, hated vomiting. He writes, “But perhaps more important is the stark fact that taking yagé is awful: the shaking, the vomiting, the nausea, the shitting, the tension.” It is, he says, “awful and unstoppable.” His description of the experience is filled with metaphors of slime and nausea. The sounds he heard “were like those of the forest at night: rasping, croaking frogs in their millions by gurgling streams and slimy, swampy ground,” “the sound of grinning stoic frogs squatting in moonlit mud.” He writes that the “collective empathizing of nausea” at the healing session “feels like ants biting one’s skin and one’s head, now spinning in wave after trembling wave.” He refers again and again to “the stream of vomit,” “the streaming nasal mucus,” “the whirling confusion of the prolonged nausea.”

But this is the reaction of a gringo. It is important to note that emetics and purgatives are widely used among the people of the Upper Amazon, who periodically induce vomiting in their children to rid them of the parasitic illnesses that are endemic in the region. Vomiting is often induced in children and adults using the latex of ojé, also called doctor ojé, which is widely ingested throughout the upper Amazon as a vermifuge; some shamans, such as don Agustin Rivas, use an ojé purge to begin la dieta. Vomiting may be induced in children by giving them piñisma, hen excrement, mixed with berbena, verbena, or ñucñopichana, sweet broom, along with other horrifying components, including pounded cockroaches and urine. I have no doubt that this is an effective emetic.

Communal vomiting is also found among indigenous Amazonian peoples. The Achuar drink a hot infusion of guayusa as a morning stimulant, much as we drink coffee, after which all of them, including the children, vomit together. Apparently the vomiting is not due any emetic effect of the drink, but is learned behavior. Here in the jungle, vomiting is easy, natural, expected; the strangled retching of a gringo comes from shame.

La purga misma te enseña, they say; vomiting itself teaches you. Giving yourself over to the plant, giving up control, letting go of shame — perhaps that is the first lesson you receive from el doctor.