Pediatric Megacystis Microcolon Intestinal Hypoperistalsis (MMIHS)

What is Pediatric Megacystic Microcolon Intestinal Hypoperistalsis?

MMIHS is a serious condition and can be life-threatening. However, with ongoing medical care and monitoring, our specialists can help your child achieve a typical, active life.

Children with MMIHS have a smaller than normal colon and an enlarged bladder. MMIHS is a rare disorder where the muscles that line your child’s bladder and intestines do not move properly. In some cases, they do not move at all.

This can affect your child’s digestive system and their ability to receive nutrition by eating and drinking. It can also affect your child’s ability to urinate, causing health issues such as:

• Inability to digest food. It may be difficult for your child to get proper nutrition. Many children with MMIHS need extra help getting nutrients into their system in a way their body can process (such as through a feeding tube).
• Intestinal malrotation. The intestines become abnormally twisted, causing blockages and affecting digestion.
• Intestinal pseudo-obstruction. The intestines act like there is an obstruction even when there isn’t one. This “imitation” obstruction can cause partially digested food to build up in the intestines, leading to vomiting, abdominal swelling and pain.
• Reduced ability to pass urine. It may be difficult for your child to empty their bladder. This can cause your child’s bladder to become larger and their abdomen to swell.

What are the signs and symptoms of Pediatric Megacystic Microcolon Intestinal Hypoperistalsis?

In pregnant women, increased amniotic fluid in late pregnancy can be a sign of MMIHS. In children, the symptoms of MMIHS can be more or less intense, depending on the severity of MMIHS. As a result, the impact MMIHS has on daily life may be different.

Symptoms can include:

• Bile-stained vomit
• Swollen abdomen
• Undescended testes (UDT) in boys
• Enlarged bladder (megacystis)
• Very small colon (microcolon)
• Sluggish or non-existent intestinal movements (hypoperistalsis)

How is Pediatric Megacystic Microcolon Intestinal Hypoperistalsis diagnosed?

MMIHS can sometimes be determined using ultrasound before your baby is born, but it is most often diagnosed shortly after birth.

The team of experts at Children’s Health starts by carefully examining your child and reviewing their medical history and symptoms. Then, lab work and a colon biopsy can help confirm if they have MMIHS.

We may also use additional tests to confirm an MMIHS diagnosis or rule out other possible causes of your child’s symptoms. Exams may include:

• Blood and urine tests
• Pediatric Find Needle Aspirate Biopsy
• Pediatric Ultrasound (Sonogram)
• Pediatric Computer Tomography (CT)
• Pediatric Magnetic Resonance Imaging (MRI)
• Genetic Testing

What causes Pediatric Megacystic Microcolon Intestinal Hypoperistalsis?

A change in the gene that helps the stomach, intestines and bladder move food and urine through the body causes MMIHS. Most of the time, children inherit MMIHS from one of their parents. However, in rarer cases, MMIHS develops with no previous family history (de novo mutation).

How is Pediatric Megacystic Microcolon Intestinal Hypoperistalsis treated?

Our specialists provide ongoing treatment that centers on your child’s bladder, kidney and digestive functions. Unfortunately, there is currently no cure for MMIHS, so long-term management is the best way to help your child be active and healthy.

We use several different treatments to help children with MMIHS get the nutrients they need to live well, including:

Nutritional Assistance

• Feeding tubes. These tubes provide nutrients by delivering food directly into your child’s stomach or intestinal tract. We offer different types of tubes depending on your child’s needs.
• Total Parenteral Nutrition (TPN). Your child receives nourishment through their blood rather than their digestive system. A mixture of electrolytes, protein, vitamins, fats and other essential nutrients flows into the bloodstream through a central line or port.

Surgical Procedures

• Catheterization. A tube (catheter) is inserted into your child’s bladder to drain urine. The process is done several times per day to reduce the strain on your child’s bladder and kidneys.
• Ileostomy. An opening is made in the wall of your child’s belly or abdominal wall. It provides a way for your child’s body to get rid of stool, which is then collected in a pouch.
• Intestinal resection. Damaged or diseased portions of the intestine are removed to improve your child’s ability to digest food.