If owners of new puppies feel that their puppy is constipated the most common cause is a fecalith. A fecalith is dried poop stuck in the hair around the anus. It is important to recognize that many times it is only a very small amount, so you have to be sure there is absolutely no poop dried in that area before you look for another cause. The fix is simple, remove any dried feces by massaging the area in a bath of warm soapy water (mild dish soap, not Dawn!) works well. Once the fecalith is removed it can also help prevent reocurrence if yse use an electirc trimmer (like for mustaches, or a pet trimmer) to clip the hair around the anus. It can still take several hours before there is normal passage of stool,. If you check and you see no dried poop at all please let me know and we can work through other possible explanations.