What Causes Constipation With Intestinal Pain?

Hi. I am a 27 year old female who has had ibs-like symptoms for a while, like gas, bloating, intestinal pain and alternating constipation and diarrhea. I also suffer from hashimotos disease, abnormally high stress levels and panic disorder. Lately I have felt the urge to go like 5-6 times daily but seem to be constipated, and will only pass small stools, if any. I feel unable to fully eliminate considering the strong urge to go... Many times instead of actual feces I will pass a blob (or 2) of strange-smelling mucous, ranging from clear to yellowish with brown and sometimes stringy looking matter within. These do not smell or look like feces, but they do smell foul and strange... What is going on with me? Could this be parasite or infection? I am somewhat concerned about colon cancer, since my father s uncle had it, yet I eat a healthy diet which is at least 90% organic.