Hi. Thanks for your query. Noted the history and understood the concerns. Since 2 feet of intestine was removed for diverticulosis of long standing duration, there can be a problem with the function of the large intestine in absorption of specific things, B-complex production and absorption and so on. Production of rotten egg smelling gas and pain indicate intestinal infection and I would advise you the following: Get the stool tested as well as blood and urine., Ultrasound of abdomen and CT scan if needed as well as colonoscopy. This will give us the proper diagnosis and proper plan of management which may be a course of an antibiotic, metronidazole. Continue the medications of Bentyl and Charcoal tablets. Take care about the diet you take and avoid all the foods and beverages that instigate or enhance the problems. Use boiled and cooled water and homemade fresh foods. Take B-complex and multivitamins.