Hola Carlos,
I am the board moderator and the mom of 2 Colombian adults. My younger son was adopted from Los Pisingos, like you. He is reunited with both birth parents. On the Los Pisingos web page you should be able to find an email contact. Send them an email and ask what the procedure is for obtaining identifying information on your birth parents. My son's birth mother and cedula number, as well as her address at the time, were on the documents we were given in order to obtain a visa for our son. Check with your parents, they may well have the information you need.
Remember too, the country of Colombia is Colombia, not Columbia.
Elizabeth Olmstead Carroll
Board Moderator