The rationale for using enemas can be traced back to the earliest medical texts, to the
prescientific misconception that the accumulation of
faeces in the intestines can lead to
autointoxication and that the "cleansing" of intestines can prevent that. The practice of
colon cleansing experienced a renaissance in the 1990s, and at this time, coffee enemas were used as alternative cancer treatments. Their frequent use is a feature of
Gerson therapy and
Kelley therapy, ineffective alternative cancer therapies. Advocates of coffee enemas often point to their inclusion in editions of the
Merck Manual through 1972, where coffee is listed as an ingredient for a
retention enema for treating
constipation. The
Merck Manual does not list any other uses for coffee enemas, and in editions after 1972 all mention of them was dropped. == Gerson therapy ==