If megacolon is left untreated, the survival period of the patient is usually about half a year, and if surgery is actively carried out, the survival period is mostly the same as that of normal people. Megacolon is mainly due to abnormal distal colonic nerve, resulting in intestinal spasm, causing proximal intestinal hyperplasia, swelling, gathering a large amount of intestinal contents, and impaired peristalsis of the colon. Patients may present with severe weakness, malnutrition, abdominal distension, constipation and other symptoms. If left untreated, intestinal perforation is likely to occur and affect the patient’s survival time. If the patient is actively treated with surgery, the prognosis is the same as that of a normal person. For patients with megacolon, it is recommended to pay attention to diet and minimize the intake of indigestible and hard food to avoid more serious damage to the colon, causing complications such as rupture, perforation and bleeding. Patients with megacolon should seek timely medical attention and early treatment under the guidance of professional physicians, and the specific survival time can also consult professional physicians.