According to your description (bump above your navel that sticks out), you may experiencing hernia. A hernia consists of three parts: the hernia’s opening, the hernia’s sack and the hernia’s containment. In this case, it seems that the opening is on the front abdominal wall and that’s why is called parietal hernia. It occurs because of defect in the muscle "rectus abdominis" at the middle of the tissue. A hernia’s sack consists of the parietal peritoneum and muscular fascia. A hernia’s containment is made up on an abdominal organ, usually the omentum or the small intestines. This can be pooled back in the abdomen (reponation) spontaneously or manually. Hernias can be potentially very dangerous conditions if the containment gets stuck and can’t make its way back into the abdomen. In that case, the vascular supply can be compromised and intestinal infarction can occur. This condition is called incarceration. Incarceration is an urgent, life threatening condition and must be treated surgically. A hernia is treated surgically. You may consult an abdominal surgeon for more details, diagnostics, and treatment.