Dogs are not bashful about constipation. If a dog is constipated, you will probably see him outside straining, obviously trying to have a bowel movement. If you're worried about your dog's bowel movements even though he's not straining, watch his appetite, activity level, and water consumption. If those things are normal, he's probably all right. Dogs who don't drink enough water.
Water consumption is important to monitor.
Drinking a lot of water, or a sudden increase in water consumption is a common sign of disease. Excessive urination is also a warning signal. But if your dog is eating the same as he usually does, has plenty of water available, and seems healthy otherwise, he is probably getting enough water. That your dog won't like you if you don't give him table scraps or treats, or if you make him do what he is supposed to do. A dog who gets into the habit of getting lots of treats is not going to be happy when you stop, but that doesn't mean he won't like you anymore.