The invention relates to a disposable absorbent item comprising an absorbent core, lateral leg elastics, a front band, a back elastic, and adhesive tape at the ends of the back elastic, characterised in that a pair of tapes are provided on the external part of the absorbent core, wherein one tape presents an indicator for detecting urine with a pH between 3 and 5, and the other tape presents said indicator in an acid solution for detecting faeces, thereby permitting a differential identification of urine and faeces.