I have pain in abdomen and increased frequency of stool after hernia surgery. Why?

Hello doctor,

I am 54 years old. Two-year post-RNY (gastric bypass surgery) I have had two Petersen hernia repairs since the surgery. The gallbladder was removed years ago. Yet since this surgery I get these horrible gut-wrenching pains from sternum to abdomen. It seems like the bowels are twisting for hours, that takes my breath away, then I go to the washroom maybe ten times within four to six hours. I can lose three to four pounds in a day. I do not seem to be constipated as I go every day or other day but perhaps I am. The surgeon does not think it is another Petersen hernia since I had two surgeries to repair them. I have had a gastro endoscope mouth to stomach (shows no ulcers and colonoscopy diagnosed with diverticulitis), a CT scan and an x-ray. I do not take medicines except for 100 mcg Eltroxin. Due to surgery, I am on a lifetime of multivitamins, B12 1000 mcg every second day and Proferrin (iron supplement). I have no allergies to foods. I never had this before when I was obese. The pain is so bad I wish for death at times and it is unpredictable. Would you have any idea what this could be? I appreciate any help you can provide.