A common gastrointestinal disorder characterised by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhoea and constipation, symptoms that tend to be chronic and wax and wane over the years. Although mucus colitis can cause chronic recurrent discomfort, it appears to be an abnormal condition of gut contractions (motility) and does not lead to any serious organ problems. Diagnosis usually involves excluding other illnesses. Treatment is directed toward relief of symptoms and includes high fibre diet, exercise, relaxation techniques, avoidance of caffeine, milk products and sweeteners, and medications. Alternative names include irritable bowel syndrome, spastic colitis and nervous colon syndrome.