Pain in the lower abdomen and left side of the belly button is associated with intestinal spasm, ulcerative colitis, constipation, and rectal disease. Intestinal spasm can be initiated in any part of the intestine, and during an attack there is spasm and contraction of the smooth muscle of the intestinal wall, thus causing pain. Although the nature of pain caused by intestinal spasm is more intense and does not last particularly long, when it commonly occurs in the left side of the intestinal tract, there is a painful sensation in the small abdomen and the left side of the belly button. Ulcerative colitis is mainly found in the colon, the left side of the navel is part of the descending colon, when the ulcerative colon is present in this part will be accompanied by pain on the left side of the navel, there will also be bloating, diarrhea, some people’s pain on the left side of the navel is located in the lower left abdomen, the nature of the stool is particularly dry, directly related to constipation. When constipation occurs due to slow intestinal peristalsis, a large amount of feces will accumulate in the sigmoid colon and rectum, thus causing painful stimulation to the intestinal wall, the rectum is located in the lower abdomen of the colon, is in the lower left abdomen of the body, when the colon area diseases such as colitis, colon polyps, colon tumors, will be accompanied by pain in the lower left abdomen of the navel.