After an emergency room visit at the end of December and, and a miserable January, I finally got in to see an insightful GI doc, we began looking for other explanations. He scheduled some tests right away including an ultrasound (came back negative for disease or injury), and a CT scan with contrast dye and barium "smoothie". Much to my shock the radiologists found a tennis-ball sized mass in my mesentery. I am just recovering from the biopsy today to determine if it is malignant, but either way it will have to come out.
So my recommendation is that, along with the usual questions about whether it might be another food sensitivity, it is very well to consider that if your symptoms become increasingly or inexplicably worse, it may be worth asking your doctor to do a thorough exam for other possibilities. Especially if they are accompanied by chills or fever.