Hi. Thanks for your query. Noted the history of lots of gases lately, smells wicked, stools are dark green and tarry. Also have pain in abdomen, like severe period pains, makes nauseous and breathless, wants to know whether to see the Doctor or is this common. With the history your have provided, the tarry stools indicate bleeding in the intestinal tract and the green color indicates infection, hence the most probable diagnosis is infection entero-colitis. I would advise you the following in such a situation: Get the stool tests for a few days. Blood tests to rule out diabetes and see for thyroid and liver functions. Get a course of an antibiotic, Metronidazole, probiotics. Also add activated charcoal, banana and yogurt to the diet. Use only boiled and cooled water to drink. And only home-made fresh food.