Punarnava (Boerhavia diffusa) is a key herb in Ayurvedic medicine, traditionally used for its diuretic and rejuvenative properties. In Ayurveda, Punarnava is often prescribed to support the body's natural detoxification processes, which are closely linked to the function of the large intestine (colon). It is believed to help regulate water balance, reduce swelling, and promote healthy elimination. Classical Ayurvedic texts describe Punarnava as beneficial for managing "Ama" (toxins) and supporting digestive health, which may include supporting the colon's role in waste removal.

However, the direct traditional use of Punarnava specifically for the large intestine (colon) is not as prominent as its use for kidney and urinary health. Some herbalists extend its use to colon health, citing its mild laxative and anti-inflammatory effects, but this is mostly based on its general detoxifying reputation in traditional practice.

Scientific studies on Punarnava have primarily focused on its diuretic, anti-inflammatory, and hepatoprotective effects. There is limited clinical or experimental research directly linking Punarnava to large intestine or colon health in humans. Thus, while tradition supports its use in general detoxification and digestive health, specific evidence for colon support is limited and not strongly substantiated by modern science.