Astanga Hrudaya
पार्श्वयोश्च व्यथा पायौ पवनस्य निरोधनम् । आमपक्वविदग्धत्वं तेषां शोफवदादिशेत् ॥ १६ ॥
catching pain in the waist and back, along with pain in the flanks, occurs if it is in the kidneys (vrikka); and the obstruction of flatus/gas occurs if it is in the rectum (payu). Expulsion of abscess contents in relation to their location with respect to umbilicus: The unripe, Ripening and Ripened Stages are similar to those of sopha (inflammatory edema).
english translation
pArzvayozca vyathA pAyau pavanasya nirodhanam । AmapakvavidagdhatvaM teSAM zophavadAdizet ॥ 16 ॥
hk transliteration by Sanscript