Hi. Thanks for your query. Noted the history and understood the concerns. Intermittent flank pain on the left side with explosive bowel movements can be due to the following reasons: Severe Entero-colitis with or without sub-acute intestinal obstruction. This can be diagnosed by the following: Tests of stool for three consecutive days. Colonoscopy with biopsy is the most important diagnostic tool that you have not yet undergone. CT scan should have been with oral and intravenous contrast a the plain CT scan may miss on certain diagnosis. A course of an antibiotic active against intestinal infection with Metronidazole and probiotics may help you. Take home-made food only and boiled and cooled water. Try to identify the foods and beverages that instigate or enhance the problems hence it will be possible to avoid them. It is good that the kidney functions are normal and CT without contrast is not showing anything to worry about. High LDL may not be associated with the present problem and hence nbot to worry about.