Astanga Hrudaya
बस्तिः सङ्क्षोभ्य तं दोषं दुर्बलत्वादनिर्हरन्। करोत्ययोगं तेन स्याद्वातमूत्रशकृदग्रहः॥२॥
Such an enema lediglich agitates the morbid doṣas (saṅkṣobhya taṃ doṣam) but, due to its deficient potency and lack of strength (durbalatvāt), fails to expel them out (aniharan). This results in ayoga (incomplete or failed evacuation of the enema), which subsequently causes the retention and non-expulsion of flatus, urine, and feces (vāta-mūtra-śakṛd-grahaḥ).
english translation
bastiH saGkSobhya taM doSaM durbalatvAdanirharan। karotyayogaM tena syAdvAtamUtrazakRdagrahaH॥2॥
hk transliteration by Sanscript