Res Ipsa Loquitur is a Latin phrase which means that the thing speaks for itself. This is a doctrine in the law of tort where a court infers negligence from the nature of the accident or the injury in absence of any direct evidence on how the defendant behaved. This works on the evidentiary rule where the plaintiffs draft a rebuttal on the presumption of negligence on the part of the defendant using circumstantial evidence.
The plaintiff has to prove that the defendant acted in a negligent manner, under this doctrine the plaintiff would put forward certain circumstantial evidence to prove the negligence, after this the burden to prove that the defendant was not negligent lies on him. Under this doctrine, the necessary elements of negligence are duty of care, breach, and causation.
For example: While operating, if the doctor leaves some swabs or any cotton pads back in the body of the patient and if he dies or there are complications due to this, then it shall be a case of Res Ipsa Loquitur.