Can antibiotics change the stool colour for yellow?and for how long?

Change in bowels: Amount, color, frequency of stool varies with foods, speed of emptying of the GI tract, medications (like antibiotics that kill health gut flora) ; supplements ingested, gut flora (unique for each individual), additives (like blood), subtractions (like absent bile), infection, inflammation, ; other factors. If stool pattern change persists, or is accompanied by other symptoms, see your doctor.