The Compendium of Caraka 3.5.8_2

3.5.8_2

annavahānāṃ srotasāmāmāśayo mūlaṃ vāmaṃ ca pārśvaṃ, praduṣṭānāṃ tu khalveṣāmidaṃ niśeṣavijñānaṃ bhavati; tadyathā---anannābhilaṣaṇamarocakavipākau chardiṃ ca dṛṣṭvā 'annavahānyasya srotāṃsi praduṣṭānīti vidyāt/

The stomach and the left flank are the root of the channels carrying food, and when these are vitiated, this is their specific diagnostic knowledge; namely: seeing absence of desire for food, anorexia, indigestion, and vomiting, one should know that his channels carrying food are vitiated.