Hello doctor, I am 28 years old female.I have been suffering from some kind of stomach problems since 3 years.At first I thought it was stomach infection but it has been reccurring every few months.Symptoms include blackish stool with mucus and chewing gum like texture..sometimes accompanied with blood..stomach pain especially after passing stool,burping sound in stomach and lot of weakness...Reports of stool test,colonoscopy and ct scan of abdomen were normal.I have taken many medicines like rifagut 400, providac,gutrex-d,colirid,lesuride, colaspa,secnil forte,pantocid d,glevo 500 etc during this period..after 10-15 days it becomes ok but reoccurs every few months...what should I do?