I'm suddenly feeling cramps below my belly button, it makes me want to go poop and pass gas. and the cramping goes away once i'm done using restroom.

IBS: 20 year old female has crampy mid-lower abdominal discomfort relieved by having bowel movement. If acute & transient then this is benign colon spasm & gas. If chronic and recurrent this might be Irritable Bowel Syndrome, IBS, & a Gastroenterologist would be best type of Doctor to evaluate. If accompanied by vomiting, fever or constant pain, then an urgent evaluation by Surgeon becomes necessary.