I have IBS. About a week ago I went to the ER with severe pain on my left side and nausea. I'm having the pain again with nausea and my diarrhea is green for 2 days now.
Diverticulitis
Sounds like an exacerbation of IBS. Use anti-diarrheals, antispasmotics. See a GI doctor if you are not better or you need chronic treatment.