I though that if you have internal hemorrhoids, then you should not consume beverages that dehydrate your body such as coffee and alcohol?

Avoid constipation: Hemorrhoids are exacerbated by constipation and the "pushing" necessary. Foods high in fat tend to constipate you. Foods high in fiber favor looser stools. Fruits vegetable, whole grains are excellent sources of fiber. Also, fiber only works if u are well hydrated. Caffeine and alcohol can increase urination so some people feel this is not as good as water, juice etc.

Internal hemarhoids : Dietary changes are arm at to avoid constipation and keep stools soft so liquids and lots of them are essential coffee and alcohol if enough liquids are on board will have little effect.