Basti is most powerful tool in the hands of a Vaidya. It is also
least explored and researched tool today. The reason is of course no
patients reluctance to ayurvedic invasive treatment. Modern science
has created scare in the minds of people, when invasion by a health
care provider comes.
Before we go further please visit to a good article from a professor
as well as vaidya on administration of basti:
http://health.groups.yahoo.com/group/ayurvedaonline/message/7094
he freely shares his experience and recommendations.
Basti can be used to tackle parasites also. author recollects
childhood experience, twice a year, either taking castor oil+milk
orally at bedtime as well as morning to clean round worms. HOme
became hospital for 2-3 days. Those siblings who would refuse due to
taste, were given basti which included castor oil in herbal
decoction. we used to get worms thrown out of bowels, for next 2 to
three days. and hunger would return in normalized form; bed wetting,
teeth crunching, anus itch would vanish. Ayurveda in india was kept
alive mainly by mothers and grand-mothers.
In  practice, author adds a little castor oil as well as decoction of
certain herbs used in treating parasites, when he administer basti to
a patient. The decoction formula varies with patient. Now how long
basti is retained depends on the method of administration. Though
basti just means herbal enema, the exact clincial procedures defers
from vaidya to vaidya. it is an art as much as surgery or giving
injection (without pain) is.
While differentiation between herbal decoction basti (Niruha) and oil
basti (Anuvasana) is for discussion sake, some recommend mixtures
too. Indeed, Niruha basti also contains a little oil, honey etc to
offer lubrication and have other effects. Dr Lad, as a part of home
panch karma advises Dashmul Kashaya+sesame oil mixture about 20
minutes after oil is administered. So you can see, ayurveda offers a
wide scope to individual thinking and there are guidelines only by
acharyas. The anuvasan basti (oil alone) is contra-indicated when
parasites are there since oil may provide them a good nutrition! see
for instance:
http://translate.google.com/translate?
hl=en&sl=ja&u=http://www.begin.or.jp/ytokoji/ayurveda/bheemabat/bheema
.htm&sa=X&oi=translate&resnum=7&ct=result&prev=/search%3Fq%3DBasti%
252Bparasites%26hl%3Den%26lr%3D
But would you not like worms to lap up the oil, if it was their
poison?
Basti is contraindicated when a person is suffering from diorrhea.
but probiotics basti helps diorrhea to reduce slowly. but
administration of such a basti is a bit tricky. The efforts in
exactitude, care, preparing decoctions etc for a single patient are
often disproportionate to the fees, which has killed the usage of
bastis.
The herbal decoctions act in a slightly dfferent manner when given
orally or rectally. many parasites and pathogens are taken care by
probiotics basti, esp. candidiasis.
And basti can be taken even when there is fever as given in the
article by authors friend, is it not adequate assurance that
pathogens are also taken care?
Since Panch Karma has so much scope and expression for individuals
thinking, one can not go strictly by "book of practice"
or "practitioners manuals" as in modern science. Patients too, should
not become surprised by difference in philosophies of Vaidyas.
The subject of bastis before conception, during last few weeks of
pregnancy and post partum is more involved and equally interesting as
it can treat several repro-genito-urinal system disorders. PCOS,
dismenorrhea, amenorrhea, menorrhagia, leucorrhea, uterus prollapse,
bladder stones, prostate enlargemnet etc are just few instances.
hence  need a separate post some other time.