I know Ash got sick with Tracy in " The Stun Spore Detour" in season 2. Did he get sick another time? If so, please list the episode's name and season. Please help me! Thank you!
Pokemon: Adventures in the Orange Islands The Stun Spore Detour Ash gets stun spored by a wild Vileplume.
Pokemon: Johto League Champions A Better Pill to Swallow Ash gets a stomachache after eating 5 hamburgers.
Pokemon: Black and White A Venipede Stampede Ash gets poisoned after helping a wild Venipede that was hurt.
Pokemon Diamond and Pearl: Battle Dimension Throwing the Track Switch Ash gets a stomachache after eating too much
Pokemon: XYZ Battling at Full Volume Ash gets sick after training with Pikachu and Greninja in a cold river in the cold night.
Ash falls sick 2 major times in the anime.
EP110: The Stun Spore Detour
XY115: Battling at Full Volume!
Sources: http://bulbapedia.bulbagarden.net/wiki/EP110 http://bulbapedia.bulbagarden.net/wiki/XY115
Well after perusing countless websites for around 45 minutes I can tell you that "The Stun Spore Detour" is the only episode Ash has ever been sick in.
Sorry I couldn't find anything else for you.