Irritable bowel syndrome (IBS) is also called spastic colon. This is a common disorder that affects the large intestine. It commonly causes symptoms like cramping, abdominal pain, bloating, diarrhoea and constipation. IBS is a chronic condition so you need to manage it for long term. This condition is caused due to combination of abdominal discomfort and altered bowel habits such as altered frequency or altered stool form (thin, hard, or soft and liquid). People will have this irritable bowel syndrome since childhood.