I vomited three weeks ago due to feeling ill, afterwards I had a sort of twitching pain in my stomach that lasted in to the next day.. Eventually the twitching pain went away. I get this severe stomach cramp whenever I hold in my bowl movement and need to go to the restroom right away. fast forward to yesterday and I had a watery stool with red, which I assume is blood. I had mucus green stool later that day. Today I am constipated and unable to use the rest room, I am feeling the twitch in my stomach again to the left side. I am going to be seeing a doctor soon.