There are many causes of pain below the belly button, which can be divided into the following categories: 1, appendicitis. When suffering from appendicitis, its main symptom is irregular pain in the small abdomen, and the pain is relatively strong. 2, intestinal diseases. For example, acute gastroenteritis, colitis, rectal cancer, rectal polyps, etc., may appear the symptoms of pain below the belly button. 3, the belly button area appears skin inflammation will also cause pain around the belly button. 4, reproductive system diseases. For example, men with prostatitis and prostate enlargement, women with uterine inflammation, uterine fibroids, uterine cancer, blocked fallopian tubes and other diseases may also cause pain in the small abdomen. Because there are many causes of abdominal pain, it is recommended that once the symptoms of abdominal pain appear, it is best to go to the hospital in time for the appropriate examination.