Bad spirit. ask it to leave immediately. IMMEDIATELY.
You will normally NOT end up with marks on your body unless the spirit itself is hurting you. I've had this experience before. ASK IT TO LEAVE. i let it stay until its problem was resolved, but on those occasions it tried to KILL me. I had handprints on my throat, and lots of scratched on my body. MAKE IT LEAVE.
Stomach and neck are chakra points, and have vitals in them. it is trying to hurt you. If they only wanted to get your attention, and it was urgent, i would have been on your arms and legs. trust me. you absolutely need to get it to leave. Angel was the only thing that saved me when i didnt ask it to leave, and even Angel was late. he had gone off somewhere, and i didnt call him when the spirit arrived. I awoke with my air supply cut off, and sent the figure to a corner of my room were i forced him to stay so Angel could return and get rid of him. (I've had lots of experiences with these things. please trust me.)
It will affect someone around you because it IS trying to hurt you. physically, or mentally, it is.
I dont mean to scare you, but i dont want a member to go missing. it is serious when they start to hurt you.