Nausea diarrhea and stomach cramps with period?

I have never had this problem before and I am not sure if it is related to my period or if it is a coincidence.

I have had five pregnancies in six years and have three besutiful kids. My youngest is 10 months old and when my periods returned 5 months ago this problem sort of started. It wasn't terrible the first time but has progressively gotten worse.

I should mention that the stomach cramps started when she was about a month old, and have been the most debilitating part. Besides the miscarriages my kids were botn via c-sections. Any one else have any experience like this?