The Compendium of Caraka 6.21.27

6.21.27

vidyādvisarpamantarjamāśu cāgnibalakṣayāt/
ato viparyayādbāhyamanyairvidyāt svalakṣaṇaiḥ//

and from the rapid loss of digestive power, one should recognize the internal visarpa. / By the opposite [of these], and by other specific symptoms, one should recognize the external one.