Hi. Thanks for your concerns. Noted the history and understood your concerns. Farting brown oily liquid out of anus on going to pass stool is indicated of the following: There can be fecolith impaction causing such symptoms. There can be an ulcer o a mass that is causing such symptoms. I would advise you the following in such a situation: Get an opinion of a General Surgeon. Per-rectal digital examination with ano-proctoscopy and colonoscopy after preparation. Biopsy if needed. X-ray of the abdomen to see if there are fecoliths and to give soap-water enema to evacuate if fecoliths are present. Tests of stool and blood. Once the diagnosis is done, an appropriate treatment can help to get you the relief and possible cure.