A nutrient enema, also known as feeding per rectum, rectal alimentation, or rectal feeding, is an enema administered with the intent of providing nutrition when normal eating is not possible. Although this treatment is ancient, dating back at least to Galen and a common technique in 19th century medicine, nutrient enemas have been superseded in modern medical care by tube feeding and intravenous feeding.
A variety of different mixes have been used for nutrient enemas throughout history. A paper published in Nature in 1926 stated that because the rectum and lower digestive tract lack digestive enzymes, it is likely that only the end-products of normal digestion such as sugars, amino acids, salt and alcohol, will be absorbed.
This treatment was given to U.S. President James A. Garfield after his shooting in 1881, and is asserted to have prolonged his life.
When the United States Senate Intelligence Committee published an unclassified summary of its 6,000 page classified report on the CIA's use of torture, its previously unknown use of "rectal rehydration" for punishment and torture became apparent.