Should i have any tests done such as blood, sputum or stool, if they have found thrush (candida) in my stomach (i think) during gastroscopy?

Not necessary: Unless you are prone to frequent infections, the likelihood that you have an immunologic problem is rare in your age group. Cessation of tobacco products is useful however.

Not necessarily: The germs of thrush, Candida Albicans are normal findings in the GI tract.It is swallowed as a random part of our ingested material and comprises 5% +/- of our stool. When present it can form irritating patches on a variety of surfaces from the mouth to the anus and beyond.Critically ill (ICU) patients may have this germ in the blood, they are normal in your spit and stool.