The abdomen is soft in normal people. If a hard mass can be touched below the belly button, it indicates an intra-abdominal mass, which may be a benign mass or a malignant tumor. Benign masses may be ovarian cysts or small bowel tumors. Ovarian cysts manifest as masses in the pelvic area of the lower abdomen, with hard texture and clear borders, and some pain when pressed. Small bowel tumor also presents as a mass in the lower abdomen, but the mass is more mobile and the boundary may or may not be clear. Malignant tumors are usually common in appendix cancer or sigmoid colon tumor, and the mass may appear below the navel when the tumor grows. Abdominal CT and ultrasound, and if necessary, colonoscopy should be performed to further clarify the diagnosis.