Woman's stark warning after a night of hell in a Balinese bar.

A businesswoman has reached out with a warning for others after she experienced a night from hell in a Balinese bar.

American Mara Wolford said she was slipped the deadly date-rape drug Rohypnol after she left her drink unattended at a local bar.

Wolford shared her story on Facebook in a post that recounted the horrors of the night alongside a very visceral image of the damage inflicted.

“I leave the drink on the bar and go to the bathroom,” she posted.

The Bali resident said she only managed to walk 20m before she fell over and scraped a large portion of skin from her face.

The Daily Mail reported the encounter as having happened at Echo Sports Bar in the Kuta area.

Wolford listed her actions as mistakes in an effort to warn others of the dangers of drinking in Balinese bars.

“All of these acts – ordering mixed drinks, not watching them being made and leaving a drink unattended – are fatal errors in Bali, but this evening, I wasn’t too concerned,” she said.

The businesswoman was said to have ordered mojitos with two friends.

“Half-way through the second … Rohypnol kicked in with fury. I knew what it was because this happened thee years ago and it was terrifying. From the speed in which this was happening, it felt like multiple doses,” she said.

The businesswoman said she warned other women in the bar before she left and the drug fully kicked in.

"I exit the bar, turn down the road, walk 20 metres and fall flat on my face, out cold," she said.

"A motorbike passes, circles back around and stops. I can remember no detail about the driver other than he was Caucasian. My face is split open."

"He was trying to clean my face up, and I remember telling him it was fine. I know what is going to happen next and I don't want him to witness it."

Wolford said she spent the rest of the night struggling to breathe as her friend watched over.

"Between projectile vomiting and loss of all bodily function, I nearly go into organ failure. I can feel my body shutting down," she said.

The Bali resident said she chose not to go to the local hospital as she felt they wouldn't be equipped to deal with her symptoms.

"I know it may sound weird that we wouldn't go straight to the hospital, but the hospitals here wouldn't know what to do either, in the case of severe benzodiazepine poisoning, and my stomach and bowels had already been purged," she said.

WA Today reported the woman later commented to say blood tests recognised a triple-strength dose of Flunitrazepam (Rohypnol) in her system.

The woman implied she would be leaving the Indonesian city after her ordeal.