My dad has no pain but burning sensation near lower back and abdomen which sometimes radiates to legs. It does not burn if he is walking or doing some activity. It only burns when he sits idle or during nights. Due to burning he is not able to sleep properly. Toilets stool is little hot as per him. Hot and sour burps sometimes. There is no problem in sitting , getting up, doing any activity, there is no pain etc. We did all types of test from basic to some advanced which included ct scan, colonoscopy etc. All reports declared where normal. No defect was found. But still it burns little from inside. It has been 1 month since happening.