LAST WISH. By Betty Rollin. Linden/Simon and Schuster.236 pp. $14.95. By Benjamin Weiser

ON OCTOBER 17, 1983, Ida Rollin died at the age of 75 in her apartment in Manhattan. A brief obituary that appeared in The New York Times a few days later gave no cause of death. Now her daughter has written a book in which she discloses for the first time how Ida Rollin died. She was suffering from ovarian cancer, and was given only a few months to live. Doctors said it would be very painful. Once it was clear that even chemotherapy would not arrest the cancer, Betty Rollin honored her mother's request and secretly helped her to commit suicide.

Last Wish is a straightforward account of a family's struggle with euthanasia. It does not attempt to analyze the larger philosophical and theoretical questions. In fact, what is extraordinary about this book is that it is an apparently faithful rendering of the event by a participant who freely admits her responsibility. Betty Rollin, then a reporter for ABC News, defends her decision to end her mother's pain as an act of compassion. Legal authorities may disagree; some could see Rollin's book as a confession of murder.

Of course, Last Wish raises troubling questions in medicine as well as in law. Ten years after the Karen Ann Quinlan case, hospitals are just beginning to discuss the circumstances under which hopelessly ill or comatose patients can be released from -- or denied access to -- respirators and other life-support systems. But Betty Rollin's mother was not on a machine. She was competent and alert. This was not merely a matter of allowing her to die, but of perpetrating her death. Once Betty Rollin realized her mother was absolutely serious about wanting to die and incapable of achieving it, she and her husband became determined to bring it about in the most efficient and painless way possible.

In the early chapters of Last Wish, Rollin describes her mother's full, exuberant life, and emphasizes their close relationship. These pages offer the implicit rationale for Rollin's complicity in her mother's suicide: Rollin, who wrote about her own battle with breast cancer and her 1975 mastectomy in First, You Cry, wants the reader to fully understand that her motives were sincere and in her mother's best interest.

Rollin devotes the second half of the book to a graphic portrayal of Ida Rollin's 21/2-year battle with cancer, and to a narrative detailing her fulfillment of her mother's last wish. In the beginning, Rollin says, her mother willingly underwent chemotherapy. But once the cancer became uncontrollable and the pain chronic, a sense of hopelessness took hold: Ida concluded that her doctors were unable to cope either with her disease or with her impending death. Rollin angrily insists that they were not honest with her mother, that they held out false hopes. Ida Rollin saw the hospital as a torture chamber and its staff as guards. She saw no reason to prolong the agony. She was bald from the anti-cancer drugs, in constant pain, perpetually nauseous and vomiting. Once, after a night of violent incontinence, she was found by a friend as she crawled on the floor of her apartment, her sheets and nightgown smeared with feces. She was disoriented from medication, and mumbled as she tried to push a towel across the rug: "Don' look. Please don' look."

Rollin spares no details of her search for the best weapon: Methods of suicide known to be effective -- arsenic, cyanide, razor blades, a gun -- were ruled out as too messy, dangerous or impractical. The many doctors she consulted, not surprisingly, refused to help. Finally, an elderly physician in the Netherlands, an American, agreed to tell her what drugs were necessary to achieve "the result you want. . . . People should have the right to end their lives when hey want to," he explained, "and if they need help to do it, so be it." The doctor is not identified in the book. He never saw or talked to Ida Rollin.

He not only recommended the drugs -- 20 100-milligram pills of Nembutal, a potent sedative, combined with Compazine, a depressive -- but he also gave careful advice about how to surreptitiously administer it: the pills should be taken with club soda; Betty and her husband should remain in Ida Rollin's apartment for two hours until she fell asleep, then depart and be sure that the doorman saw them; Ida would die in about six hours; someone else should find her body, and then her doctor should be called. "If everything goes smoothly, the doctor will write on the death certificate that your mother died of natural causes," he said. "If there's a suspicion of suicide there'll be an investigation. You don't want that."

ROLLIN says that after learning of her plan, her mother spent her final days a cheerful woman. They agreed upon a date and time for her dath. Betty's husband secured the pills. A friend was recruited to "discover" the body. Rollin emphasizes that until the final moment, she did not encourage her mother to take the pills, and always searched for clues that she had become hesitant or changed her mind. Ida Rollin never wavered. When Betty needed reassurance that they were doing the right thing, her mother gave it. Her husband also reminded her that they needn't worry so much because "we weren't driving, she was"; they were "only navigators." Rollin discloses that she was stunned, shaken, then thrilled as she watched her mother calmly swallow the pills.

Why were Betty Rollin and her mother forced to act as they did? The medical profession, which has become remarkably adept at prolonging life, is still deeply uncomfortable with the issue of willfully shortening it. Hospices, with their philosophy of pain control (and their refusal to extend dying patients' lives) are slowly gaining wider acceptance among Americans, but the demand still exceeds the supply. Rollin says that she looked into the possibility of a hospice for her mother, but there were no beds available. A psychiatrist who heard about Ida Rollin's case said she should be given anti-depressant medication. Betty rejected that option. And she maintains that Ida Rollin's own doctor effectively disappeared in the end: insensitive, incapable of dealing with her wishes.

Many who read Last Wish -- especially doctors -- will deplore Rollin's act. She makes no attempt to disguise her strong bias and as much as she wants to be the objective reporter, she remains the devoted daughter, and this may raise some questions about her judgment. There is no explanation of her reporting technique, and how she reconstructed the hundreds of conversations that are quoted throughout the book with her mother and doctors. To ultimately have faith in Rollin's decision requires a reader to have absolute confidence in the accuracy of her facts and the representations of her mother's state of mind.

However, this does not undermine her central argument: that doctors who claim to be ultimately responsible for a patient's care did not provide the answers or the help Ida Rollin wanted. Betty Rollin challenged the ancient Hippocratic oath, which says physicians shall "do no harm." Perhaps a new interpretation is needed. The book implies that the doctor from the Netherlands had given similar advice to other patients. Such cases are probably more common than the medical profession cares to admit. It should not be the responsibility of a sick patient who is in desperate pain to make that decision alone; or of a family, which may be too emotionally involved, or whose motives may be mixed. A solution may be the committees recently established in some hospitals to handle the difficult ethical issues involving life-support therapy. When doctors turned away from Betty Rollin, they were indicating they wanted no responsibility for her decision. Even if they personally disagreed with her request and saw it as a cry for help, they misconstrued the precept of doing no harm. The harm was in ignoring her.