The invention relates to a capsule or chip or sensor comprising a marker/detector and signalling device/method associated with the development of a medical condition/disease and to its use. This In Situ Lab On a Chip Signalling device (ISLOGS device) is used for detecting a medical condition/disease in situ or in vivo (inside the body), for example by swallowing it for testing in the digestive tract or by putting it into the vagina, mouth or nose. All reactions takes place in the body and when the test result is positive the device will notify the subject by colorizing the tested body fluid or biomaterial (for example faeces, urine or saliva) or the device itself. The detection is made outside of the body when the biomaterial or ISLOCS device has left the body.
