Charak Samhita
बस्तौ, बस्तौ प्रणीते च वर्तिः पीनतरा भवेत्। त्रिरात्रं कर्म कुर्वीत स्नेहमात्रां विवर्धयेत्॥६९॥
This uttarabasti should be done for three consecutive nights with gradual increase in the dose of unctuous medicament.
english translation
bastau, bastau praNIte ca vartiH pInatarA bhavet। trirAtraM karma kurvIta snehamAtrAM vivardhayet॥69॥
hk transliteration by Sanscript