I have been experiencing a variety of weird symptoms such as very frequent diarrhea, troublesome periods (heavy, fiberous, cramping), and very bad gas pains in lower abdomen?   My gyno sends me to the Internist but the internist says it's just IBS... but I feel this is different it always gets intense with my cycle.... any advice?

Optional Information:
Female , Age: 40

Already Tried:
managing IBS which doesn't help. Charting all changes. I am also experiencing more Indegestion or heartburn