How often are you able to visually spot some type of infection (not necessarily h. pylori) in the stomach (not including ulcers) during an endoscopy? Or must you wait for the results of the biopsy?

Excluding Hp, it would be very unusual to have an infection in the stomach, UNLESS one is profoundly immunosuppresed. Cultures are always required to confirm the diagnosis.

A few exceptions- esophageal candidiasis has a classic endoscopic picture and is easily diagnosed. Whipple's disease (T. whippili) can infect the duodenum, but a biopsy is required to confirm the diagnosis.

Crypt