Garudapurana 1.158.14

1.158.14

bhallātakāsthisaṃsthānā raktā pītā sitāśmarā /
bastirnistudyata iva śleṣmaṇā śītalo guruḥ //

it is shaped like a marking-nut seed, red, yellow, or white. / Due to kapha, the bladder feels as if pierced with needles, cold, and heavy;