For Two Days I Have Had Dull, Mild To Moderate

For two days I have had dull, mild to moderate pain in my left side beneath my lower ribs. Sometimes it resembles a pulled muscle, but I did nothing to strain or bruise the ribs. Other times it feels like gas and there is some pain increase when palpating the area or taking a deep breath. About ten days ago I had nausea, very foul-smelling diarrhea and vomiting. The vomiting was just a single episode and I was able to drink and keep water in my stomach, but the diarrhea continued for a couple of hours. I was quite fatigued afterwards and slept for the next day. I am wondering about the current symptoms and if they may be related to the earlier situation. I have been treated for GERD.