Adult navel bulging a soft bag, may be navel inflammation, umbilical hernia, colon cancer and other diseases caused by the patient should seek medical attention in a timely manner to clarify the cause of treatment. 1. navel inflammation: staphylococcus aureus and other infections caused by the navel inflammation, in addition to the navel bulging a bag, the patient will also have local redness, swelling, pus outflow and other symptoms, can be local use of hydrogen peroxide and other drugs for treatment. 2. Umbilical hernia: that is, the hernia sac protrudes through the umbilical ring, there will be a soft local bag, usually painless, when strangulation or incarceration occurs, there will be severe vomiting and pain, can be treated by surgery. 3. Colorectal cancer: if there is a soft bag protruding from the navel of an adult with symptoms such as abdominal pain, diarrhea and bloody stools, it should be considered as a malignant tumor protruding from the colon, and the patient should actively prepare for surgery. All the above treatments should be carried out under the guidance of a doctor.