Chickens will drink more in hot weather, and will regurgitate when eating at a low level. Keeping waterers in the shade at the proper height (top of trough at the same level as the lowest height of their back) and doing the same with feed troughs will help prevent regurgitation. It is important to keep waterers and feeders clean to avoid bacteria/algae.
If birds are crop bound, that is whole different story. Keeping grass cut around range areas prevents birds from ingesting the more course and undigestable matter. Make sure birds have access to mineral grit. Birds that are 3 months old should still be receiving a coccidiosis preventative around every three weeks if you have them off medicated feed. Good ventilation in the coop, and keeping coop litter dry is important also. Provide more than one water station and feed station depending on how many birds you have.
