Frequent night pain inside the navel is usually caused by roundworm infection of the intestinal tract, biliary tract or duodenal ulcer and other diseases. 1. Roundworm infection of the intestinal tract or biliary tract: especially roundworm infection of the small intestine or biliary tract, because roundworms are more active at night, can stimulate the small intestine or biliary tract, producing pain at night. And because the small intestine is located below the navel, so you will feel pain inside the navel. 2. duodenal ulcer: duodenal ulcer has fasting pain, eating pain relief characteristics. General night and day eating time interval is long, in the fasting state, duodenal ulcer will attack, causing pain. The duodenum is located around the navel, which may be mistaken for pain inside the navel. It is recommended that patients with frequent night pain inside the navel, there may be other parasitic infections or other diseases, so it is recommended to go to the hospital in a timely manner, after a clear diagnosis to be treated accordingly, so as not to delay the condition.