I have been having stomach pain for a while now. back and forth between painful bloating or diarrhea. what could be causing this?

Abdominal pain : If this is going on for long time you need to see your 1ry care physician for examination, workup & evaluation, multiple conditions can cause these symptoms. At the mean time go on bland low fat diet, no spices & no dairy & see if that would help alleviate your symptoms until you get to see your doctor. Feel better.

Irritable bowel??: It almost sounds like you could have irritable bowel syndrome. The criteria for diagnosis are: "recurrent abdominal discomfort on at least 3 days month for the last 3 months associated with two of the following: Improved symptoms after bowel movement, onset of symptoms associated with a change in frequency of bowel movement, onset associated with a change in form of BM. Use Metamucil to help.