One of the most common reasons for a larger stomach after open heart surgery is the development of an incisional hernia. This is mainly due to the increase in intra-abdominal pressure after open heart surgery, such as when some people have a violent cough, suffer from constipation or get out of bed too early for strenuous activities. The organs in the abdominal cavity will protrude through the open wound to the outside of the abdominal wall, and the abdomen will become larger especially when standing, and smaller when the patient lies down or presses down with the hand. This condition is recommended to be diagnosed by abdominal CT or ultrasound, and if an incisional hernia is present it should be surgically repaired.