Toxic Megacolon: Causes, Symptoms & Treatment

Toxic megacolon is a life-threatening complication of various bowel diseases. The colon becomes massively enlarged and septic-toxic inflammation occurs.

What is toxic megacolon?

Toxic megacolon is defined as acute dilatation of the colon with clinically prominent inflammation of the colon. Various diseases and, in particular, diseases of the colon may be considered as causes. However, the exact pathomechanism is not yet known. Patients with toxic megacolon suffer from severe pain and high fever. There is a risk of perforation of the intestine with leakage of intestinal contents into the abdominal cavity. Severe bleeding or even shock can also be consequences of toxic megacolon.

Causes

The most common cause of toxic megacolon is ulcerative colitis. It is a chronic inflammatory bowel disease that occurs in episodes. It spreads continuously from the anus to the mouth. Ulcers of the upper mucosal layers are typical of the disease. If the inflammation spreads to all layers of the intestinal wall, toxic megacolon may result. Toxic megacolon can also develop in Crohn’s disease. Crohn’s disease is also a chronic inflammatory bowel disease. Here, however, the posterior section of the small intestine and the colon are preferentially affected. The inflammation spreads discontinuously, but penetrates all mucosal layers. The cause of toxic megacolon can also be pseudomembranous colitis. This usually occurs after prolonged antibiotic therapy. Antibiotics kill not only the pathological bacteria, but also the physiological bacteria of the intestinal flora. As a result, antibiotic-resistant strains can proliferate. One species of this type is the bacterium Clostridium difficile. The bacteria colonize the entire colon and secrete toxins that cause a severe inflammatory response. Rarely, toxic megacolon is caused by Chagas disease. Chagas disease is caused by the protozoan species Trypanosoma cruzi and is most common in South America and the southern United States. Hirschsprung’s disease can also result in toxic megacolon. This congenital disease is associated with an alteration of the neuronal structures of the intestinal wall nervous system. The pathway by which these disorders cause pathological enlargement of the colon has not yet been clarified. It is possible that various messenger substances, known as inflammatory mediators, cause muscle relaxation, which leads to dilatation and bulging of the intestine.

Symptoms, complaints, and signs

The main symptom of toxic megacolon is a distended painful abdomen. Because of the defensive tension, the abdomen feels hard. The fever is very high. This is referred to as a septic temperature. The heart beats very fast (tachycardia). Because of the severe inflammation, intestinal obstruction occurs. Stool and intestinal winds can no longer pass. Affected individuals may vomit feces. Untreated toxic megacolon can progress to shock. Multi-organ failure is also possible. When the megacolon perforates, intestinal contents spill into the abdominal cavity. Life-threatening inflammation of the abdominal cavity and peritoneum (peritonitis) occurs.

Diagnosis and course of the disease

Toxic megacolon is diagnosed by x-ray. For this purpose, a so-called abdominal empty image is taken. There, a distended colon is visible. Normally, haustra are found in the wall of the colon. Haustren are bulges in the colon wall that segment the colon. In toxic megacolon, the haustren have disappeared. There may be free air in the abdominal cavity. There are increased leukocytes in the blood count due to the severe inflammation. Thus, leukocytosis is present. The electrolyte balance is disturbed, anemia may be evident. The erythrocyte sedimentation rate is markedly increased.

Complications

Toxic megacolon always represents an emergency and must be treated accordingly and quickly. If this is not done, the resulting intestinal obstruction and accumulation of toxins in the body will lead to the death of the affected person after a certain time. If left untreated, this often results in perforation of the damaged large intestine, which eventually releases toxins and other substances into the abdominal cavity. The result is life-threatening internal sepsis.Shock and multiple organ failure are also possible consequences if the disease is not treated. Furthermore, there may be a rapid drop in blood pressure due to massive blood loss (from bloody diarrhea). Treatment in a conservative way can be successful, but it is also possible that there is no improvement within a few days. In such cases, surgical intervention is required. For the person affected by toxic megacolon, this means a permanent loss of colon tissue or of the entire colon and rectum. Accordingly, the affected person is subsequently dependent on an artificial bowel outlet for life, insofar as a large part of the colon had to be removed. Toxic megacolon itself is already a serious complication of inflammatory bowel disease (for example ulcerative colitis or Crohn’s disease). All complications in this context can still occur during treatment.

When should you see a doctor?

Disorders of the gastrointestinal tract, digestion, and irregularities in toileting should be presented to a physician. An elevated body temperature, a general feeling of illness, and malaise indicate a disease. A doctor is needed so that clarification of the cause can take place. Heart palpitations, irregularities of the heart rhythm as well as an internal weakness are further complaints for which a visit to the doctor is necessary. If intestinal obstruction occurs, a visit to the doctor should be made immediately. A decrease in the usual physical strength, an inner restlessness as well as faintness and exhaustion are signs of a health disorder. If daily obligations can no longer be fulfilled, action is required. Irritability, sleep disturbances or other dysfunctions must be discussed with a doctor. Vomiting of feces is characteristic of the disease. If this occurs, a physician should be consulted as soon as possible. It can become life-threatening if medical care is not initiated. Pain in the stomach or intestines, induration below the rib cage, and swelling should be investigated and treated. Blood loss, a sharp drop in blood pressure, and pale skin coloration should be understood as warning signs from the body. In acute situations, an emergency physician should be called. The affected person is at risk of blood poisoning, massive blood loss or damage to the organs without intensive medical care.

Treatment and therapy

Toxic megacolon is acutely life-threatening and therefore an intensive care emergency. Treatment is given with constant monitoring of the patient. The main goal is to rapidly relieve the colon and balance the impaired electrolyte and fluid balance. In addition, the accumulating toxins must be eliminated. Therapy is usually conservative in nature. Sufferers receive plenty of fluids and also broad-spectrum antibiotics. Glucocorticoids are also used. If this does not lead to improvement, leukocyte apheresis (LCAP) may be used. Apheresis is a type of blood washing. In this process, the blood is passed through a tube into a system. There, white blood cells such as lymphocytes, granulocytes, monocytes and also platelets are removed from the blood. Then the filtered blood is returned to the body. This is to reduce inflammation. In addition, ciclosporin A and monoclonal antibodies may be prescribed. If there is no improvement within 48 to 72 hours, surgical intervention is required. In surgery, the colon and rectum are partially or completely removed. An ileostomy is created to drain the stool. The ileostoma is an artificial intestinal outlet (anus praeter). In this case, a deep loop of small intestine is passed out through the abdominal wall in the area of the right lower abdomen. If the colon has been completely resected, the ileostoma must be permanently retained and is then used for the terminal diversion of the bowel contents. Double-barrel ileostomies are created transitionally to relieve the inflamed colon. They can be removed after healing.

Prevention

Toxic megacolon can be prevented only by early and effective therapy of the underlying disease. Chronic inflammatory bowel disease is treated with cortisone preparations, immunosuppressants, or TNF-alpha blockers. It may be necessary to intervene surgically before toxic megacolon develops.Pseudomembranous colitis is treated with antibiotics. Another option is stool transplantation. Antiprotozoal drugs are used to treat Chagas disease. Children with Hirschsprung’s disease need surgery as early as possible. The affected segments of the colon are removed and the bowel is relieved by an artificial bowel outlet before toxic megacolon develops.

Follow-up care

In about 40 percent of all cases, toxic megacolon leads to the death of the affected person. Aftercare then focuses on survivorship therapy. To cope with grief, regular psychotherapeutic treatment is indicated for first-degree relatives. In the remaining 60 percent of cases, toxic megacolon can be treated conservatively or surgically, depending on the severity and the decision of the specialist. In the case of conservative therapy, the task of follow-up care is to continue to maintain the clinically stabilized and improved condition of the affected person. For this purpose, the further course of the disease is closely monitored clinically and also radiologically after the clinical stay. In addition, regular laboratory tests of the patient’s blood and stool must be performed. These measures are intended to prevent the indication for surgery from spreading. After surgery for toxic megacolon, the range of necessary follow-up examinations and treatments is very diverse. This is because as a result of the surgery, either only the affected section of the colon or the entire colon may have been removed. In addition, an artificial anus is regularly created. As self-help measures, a low-fiber diet and sufficient fluid intake are recommended after surgical treatment. Patients should also divide their regular meals into numerous smaller meals. The intestine can thus relearn its normal function as the disease progresses.

What you can do yourself

Consultation with a physician is not always indicated. Sick people can sometimes cure an ailment like a cold on their own. Rest and quiet help the body recover. Toxic megacolon, on the other hand, is a serious and life-threatening condition. Self-treatment is out of the question in this case. Surgery is performed on a regular basis. Patients with the typical symptoms should seek medical treatment immediately. Self-therapy does not promise recovery. A mortality rate of about 50 percent does not allow self-treatment apart from scientific knowledge. However, those affected can do a number of things to support recovery. Above all, relaxation and rest have a positive effect on healing. Sporting activities should be completely stopped immediately after an operation and then only gradually resumed. The attending physician will be happy to advise patients on this. The diet should also be changed. It is advised to eat many small meals. Low-fiber foods are preferable. The intestines must first get used to their normal functions again after treatment. An adequate and non-alcoholic fluid intake supports it in this process. The transport of stool can thus be restarted.