loose and yellow stool normally means some sort of insufficient bile output. Also, an intestinal infection can cause loose yellow stool, along with Gastroesophageal reflux disease
Stools are loose and yellow because, there may be any infection in the food. The yellow color is due to the food digested. Kindly made a test on the stool there may be infection by e. coli or e. h. cysts this is quietly call to be hook worm. it can be controlled by taking any antibiotics which prescribed by the doctors.
You need to consult what you have been eating, or not eating. Changes in stools indicate dietary changes, or insufficiencies. If you are having bowel disorders, you may be ill.