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.
The exact cause of irritable bowel syndrome is unknown. It is called a syndrome because it causes a wide range of symptoms that range from gas, bloating, and pain to constipation and diarrhea. Excessive stress, (either emotional or physical) can trigger flare-ups as can the wrong foods, hormonal variations, and even changes in activity patterns.