Distension of the ascending colon is often caused by an increase in the contents of the ascending colon, such as gas accumulation in the intestine, constipation, as well as polyps and even malignant tumors, among others. However, it is difficult to define the symptom of distension of the ascending colon. The ascending colon is located on the right side of the abdomen, and many other diseases may also cause pain in the right side of the abdomen. For example, in appendicitis of the lower right abdomen, in addition to abdominal pain, there may be fever and elevated white blood cells. Another example is the right upper abdominal pain in various biliary and gallbladder diseases, such as cholecystitis, gallbladder stones, gallbladder polyps, bile duct stones, and other lesions. Therefore, to identify the cause, it is best to have the relevant tests.