Hi there! I am also an IBS C. For me, when I am having a long bout of C, I follow this recipe:
In the morning, have a warm cup of water with lemon juice (as another suggested--try to stay away from honey as all forms of sugar can be constipating) and a bowl of oatmeal. About 30 mins later, sit on the toilet for 10 mins and try to relax (read a book). Whether you go or not, follow this recipe for the rest of the day:
Eat a lunch with lots of green veggies (insoluble fiber, I know, try to pop a few more SFS beforehand and have a sweet potato or carrots as your soluble fiber, not white bread or pasta). Try a bunch of cooked spinach, green beans, etc.
In the evening, have a peeled apple, 1/2 banana or a pear.
You obviously drink plenty of water. My only other note would be to point out that on days when I did not consume enough food/calories, no matter how well I ate (health-wise), I could not go the next morning.
You can also try taking a warm bath, which I find loosens you up.