Family Life What is Metamucil sunrise? What is Metamucil sunrise? This medication is used to treat constipation. It increases the bulk in your stool, an effect that helps to cause movement of the intestines. It also works by increasing the amount of water in the stool, making the stool softer and easier to pass. Related Posts:How do you make Metamucil easier to drink?Does miralax and Metamucil work the same?How much Metamucil should I give my 10 lb dog?Is Benefiber discontinued?