Each dosha has a season and a therapy. Spring is Kapha's and belongs to vamana. The rains are Vata's and belong to basti. Autumn is Pitta's, and belongs to virechana — therapeutic purgation, which removes Pitta from its own seat in the small intestine and the liver region.
As with basti: this is a clinical procedure with preparation, dosing and aftercare, and it is not something to arrange from a newsletter. If you work with a practitioner, this is the fortnight to raise it. What follows is the principle, which is usable by anyone.
The principle is bitter. Of the six tastes, bitter is the one modern eating has almost completely removed, and it is the one that most directly answers Pitta. Bitter is cooling, drying and light; it clears heat from the blood, supports the liver, reduces itching and skin eruption, and — the detail people find surprising — it is the taste that most reliably restores a distorted appetite rather than suppressing it.
Where to find it without a pharmacy: bitter gourd, the bitterest greens you tolerate, fenugreek leaves, turmeric, radish greens, dandelion if you have it, and a little neem if you are willing. The traditional herbs of the season are frankly unpleasant and that is the point — guduchi, kutki, chirata, kalmegh, neem, daruharidra. Aloe is gentler. Amla is the outlier: sour to the taste but cooling in effect, and the single most useful thing in a Pitta autumn.
A reasonable household-scale version of the season's therapy, for anyone without a practitioner: a fortnight of bitter greens daily, ghee at the main meal, no alcohol, no fermented food, and a genuinely early dinner. That is not virechana and should not be called it — but it is the same direction of travel, and it is safe to do on your own.
Not for everyone. Purgatives are contraindicated in pregnancy, in weakness or depletion, in acute illness, and in the very young and very old. Bitter in food is fine; bitter as a purge is a clinical decision.