Bad oral hygiene can lead to sour taste. Excess use of tea, caffeine, cocaine and tobacco can cause sour mouth. Injuries to nerves or brain can lead to sour taste. If you are suffering with depression, stress disorders or anxiety, it may also be a cause of sour taste in the mouth.
Health conditions. Certain health conditions can cause symptoms of flatulence, including: 1  indigestion. 2  constipation. 3  irritable bowel syndrome (IBS) â a common digestive condition, which can cause stomach cramps, bloating, diarrhoea and constipation. 4  coeliac disease â an intolerance to a protein called gluten, found in wheat, rye and barley.
Having too much protein in too large a meal is a common cause of digestive problems and excessive flatulence. Undigested protein can putrefy in the heat of the large intestine and, with bacterial action, lead to the production of gases like hydrogen sulphide, indoles, skatoles and mercaptans.