Can antibiotics trigger gallstone attack or can diahrrea trigger an attack?

Probably not: If you have gallstones then what will trigger an attack is contraction of the gallbladder and getting a stone blocking the duct that drains the gallbladder. Antibiotics wouldnt do this. Usually the cause is eating, particularly fatty foods. If you have gallstones you shoud consider having surgery to remove it before it becomes an emergency.

Possibly ? rare?: Although it is not common for antibiotics or diarhea to cause a gallbladder attack(biliary colic or acute cholecystitis), gastrointestinal problems can alter motility which in turn may effect gallbladder function. We do know that patients who are very sick can develop acute acalculous cholecystitis (without having gallstones).