Get an endocrinologist to check you for hyperthyroidism, that could account for both of your issues!
Well, could be you're just plain constipated, and that's why you have this continual urge to go and not much comes out. Since it's only been going on two weeks, eat more fiber foods, exercise more regularly, and drink some extra water. Especially eat oat cereal every morning. You could additionally try an enema and see if it will loosen up the constipation, or use an over-the-counter laxative type medicine.
As for your ideas about bipolar and mania, I don't see that in your post. What I DO see is someone who is a nervous wreck. It is very possible that your constipation came about when you went through a particularly stressful week, and so you just didn't pass waste. This is very common. Digestion issues alone can make a person feel jumpy. And then there's stress. If you will spend a little time thinking about how your days go, and how you wish they would go, the answer should come very quickly as to what your "life stressors" are. Might be you aren't sleeping too good, that can really wreck your day. Could be you're not eating right, could be you just finished a bunch of final exams, or could be you hate your boss. Lots of stuff. Hope these ideas help you.