Congenital and acquired megacolon: symptoms and how to treat

The megacolon is the dilation of the large intestine, accompanied by difficulty in eliminating feces and gases, caused by lesions in the nerve endings of the intestine. It can be a consequence of a baby's congenital disease, known as Hirschsprung's disease, or it can be acquired throughout life, due to Chagas disease, for example.

Another form of megacolon is due to acute and severe intestinal inflammation, called toxic megacolon, which is usually developed by people with inflammatory bowel disease, causing intense bowel dilation, fever, rapid heartbeat and risk of death.

With the loss of bowel movements and contractions in this disease, signs and symptoms appear such as constipation that worsens over time, vomiting, bloating and abdominal pain. Although there is no cure, the megacolon can be treated according to its cause, and consists of the relief of symptoms, with the use of laxatives and intestinal washes, or in the performance of surgery to remove the affected part of the intestine, correcting in a way more definitive changes.

Main signs and symptoms

Due to impaired bowel movement capacity, megacolon signs and symptoms include:

• Intestinal constipation, or constipation, which worsens over time, and can even stop stool and gas elimination; Need to use laxatives or intestinal lavage to evacuate; Bloating and abdominal discomfort; Nausea and vomiting, which can be severe and even eliminate the contents of the stool.

The intensity of these symptoms varies according to the severity of the disease, so the symptoms can be noticed in the first days of life, as in the case of congenital megacolon, or can be seen after months or years of onset, as in case of the acquired megacolon, as the disease progresses slowly.

Main causes

Megacolon can happen for several reasons, which can arise from birth or be acquired throughout life. The most common causes are:

1. Congenital megacolon

This alteration, known as Hirschsprung's disease, is a disease that is born with the baby, due to a deficiency or absence of nerve fibers in the intestine, which prevents its proper functioning for the elimination of feces, which accumulate and cause symptoms.

This disease is rare, caused by genetic changes, and the symptoms can already appear from the first hours or days after birth. However, if the changes and symptoms are mild, it can take weeks or months to correctly identify the disease and, in these cases, it is common for the baby to have a delay in growth, due to a lesser absorption capacity of the nutrients of the foods.

How to confirm: the diagnosis of congenital megacolon is made by observing the child's symptoms by the doctor, carrying out a physical examination, in addition to requesting tests such as an x-ray of the abdomen, an opaque enema, anorectal manometry and rectal biopsy, which allow the disease to be confirmed..

How to treat: Initially, a temporary colostomy surgery can be done to allow the baby to pass stool through a small bag that is attached to the belly. Then, a definitive surgery is scheduled, around 10-11 months of age, with removal of the impaired intestinal part and restructuring of the intestinal transit.

2. Megacolon acquired

The main cause and acquired megacolon is Chagas disease, a situation known as chagasic megacolon, which occurs due to lesions in the intestinal nerve endings caused by infection with the protozoan Trypanosoma cruzi , transmitted by the bite of the barber insect.

Other causes of dilation and stopped intestinal functioning that are acquired throughout life are:

• Cerebral palsy; Diabetic neuropathy; Spinal cord injuries; Endocrinological diseases such as hypothyroidism, pheochromocytoma or porphyria; Changes in blood electrolytes, such as potassium, sodium and chlorine deficiencies; Systemic diseases such as scleroderma or amyloidosis; chronic use of constipating medicines, such as anticholinergics and anti-spasmodics, or laxatives;

The megacolon can also be of the functional type, in which the exact cause is not known, but which probably originates due to a chronic, severe intestinal constipation that is not properly treated and worsens over time.

How to confirm: in order to diagnose the acquired megacolon, an evaluation by the gastroenterologist or coloproctologist is necessary, who will analyze the clinical history and the physical exam, and order exams such as an x-ray of the abdomen, an opaque enema and, in case of doubts as to the cause intestinal biopsy, allowing confirmation.

How to treat: the treatment is done to allow the elimination of feces and gases by the intestine, and can initially be done with the help of laxatives, such as Lactulose or Bisacodyl, for example, and intestinal washes, however, when the symptoms are intense and with little improvement, a coloproctologist removes surgery on the affected part of the intestine.

3. Toxic megacolon

Toxic megacolon is an acute and serious complication of some type of intestinal inflammation, mainly due to Crohn's disease or ulcerative colitis, although it can be associated with any type of colitis, whether due to an intestinal torsion, diverticulitis, intestinal ischemia or a colon cancer obstruction.

During a condition of toxic megacolon, there is an intense dilation of the intestine that has a fast, severe evolution and that causes the risk of death, due to the intense inflammation that happens in the body. In addition, signs and symptoms appear, such as fever above 38.5ºC, heart rate above 120 beats per minute, excess of white blood cells in the bloodstream, anemia, dehydration, mental confusion, alteration of blood electrolytes and drop in blood pressure.

How to confirm: the confirmation of the toxic megacolon is made by medical evaluation through an x-ray analysis of the abdomen, which shows an intestinal dilation greater than 6 cm in width, physical examination and clinical signs and symptoms.

How to treat: The treatment is aimed at controlling symptoms, replacing blood electrolytes, using antibiotics and other drugs to reduce intestinal inflammation, such as corticosteroids and anti-inflammatories. However, if the disease continues to worsen, surgery for total removal of the large intestine may be indicated as a way to eliminate the focus of inflammation and allow the affected person to recover.