Will drinking plenty water reduce water retention and help show abs? do anti-diarrhea drugs cause water retention? i not sick, just want a better bod

Water retention: Drinking plenty of water will reduce rebound water retention, which occurs when your body is dehydrated and tries to hold onto as much water as it can to compensate. If the person is thin enough and has good muscle tone, their abs might look better due to less bloating. Diarrhea is very dehydrating, so it might cause rebound water retention. Thus, someone on anti-diarrheals might retain water.

No shortcuts to abs.: The above answer is an excellent simplification of a complex topic: fluid and electrolyte balance. No one food or supplement will enhance your ab's. Exercise your core and maintain a normal body habitus. Check your BMI as a guide. It's boring advice, but healthier.