After many visits, including a 2 CT scans, an MRI with contrast, x-rays, and an ultrasound, I was left with the explanation that it was simply constipation pains, and to take the
prescription Amitiza, which I complied with until it stopped working.
I then visited a different Doctor, who immediately after feeling my left side, said that she knew what was wrong: my Sigmoid colon was not completely emptying, despite my stool being liquid from the laxatives.