I had what I thought was an IBS attack on Sunday, Tuesday midnight started again, going on 24 hours...diarrhea and pain. Help?

These don't sound... ...like typical IBS symptoms. People with IBS can have other gastrointestinal problems as well. On a personal note, I had IBS for years and, like you, had a particular severe and lengthy attack. It turned out it was a G.I. bleed & a partial small bowel blockage. I needed a blood transfusion and surgery. I wouldn't be alive today if I'd waited one more day. Please get care ASAP!