Computer Abuse Amendments Act of 1991 - Amends the Computer Fraud and Abuse Act to make it a felony to knowingly transmit an unauthorized program or code that alters the information stored in a computer with the intent to damage the system or information contained within the affected computer or computer system, or to withhold or deny the use of such system or information, if the transmission: (1) occurred without the authorization of the person responsible for the computer system receiving the program; and (2) causes damage exceeding $1,000 in any one-year period or modifies or impairs the medical care of one or more individuals. Makes such offense punishable by a fine and up to five years in prison.

Sets forth parallel provisions with respect to recklessly transmitting a destructive computer program or code. Makes such offense a misdemeanor, punishable by a fine and imprisonment for up to one year.

Creates a civil cause of action for compensatory or injunctive relief for persons suffering damage or loss by virtue of a violation of this Act. Limits damages to economic damages, except for medical records violations. Sets a statute of limitations of two years from the date of the act complained of, or from the date of discovery of the damage.

Requires the Attorney General to report to the Congress annually during the first three years following the date of enactment of this Act concerning prosecutions under this Act.

Repeals provisions which exclude automated typewriters and typesetters, portable hand held calculators, and similar devices from the definition of "computer."

Modifies the prohibition against accessing a Government computer where such conduct affects the use of the Government's operation of such computer to cover only actions that "adversely" affect such use.