Hernia (inguinal or umbilical)

In most individuals with MPS I, the abdomen bulges out due to their posture, weakness of the muscles, and the enlarged liver and spleen. Frequently, part of the abdominal contents will push out behind a weak spot in the wall of the abdomen. This is called a hernia. The hernia can come from behind the navel (umbilical hernia) or in the groin (inguinal hernia). Inguinal (groin) hernias are often repaired by an operation, but hernias will sometimes recur. Umbilical (navel) hernias are not usually treated unless they cause entrapment of the intestine (intestine gets caught in the abdominal opening, which cuts off its blood supply) or are very large and are causing problems.

An individual affected by MPS I with a hernia
Courtesy of Hodder/Arnold Publishers

Bowel problems

People affected with MPS I Hurler disease suffer periodically from loose stools and diarrhea. The cause of this is not fully understood. Occasionally, the problem is caused by severe constipation and leakage of loose stools from behind the solid mass of feces. More often, however, it “comes straight through.” It is thought that there may be a problem with the autonomic nervous system, the system that controls those bodily functions usually beyond voluntary control. Studies have found GAG buildup in the nerve cells of the intestine, and it seems likely that the diarrhea is caused by abnormal movement of the bowel.

An examination by a physician, supplemented by an X-ray if necessary, may establish the cause. For children, the problem may disappear as the child gets older, but it can be made worse by antibiotics prescribed for other problems. If the diarrhea in some individuals with MPS I appears to be affected by the diet, it can be helpful to eliminate some foods. If antibiotics have caused the diarrhea, eating plain live-culture yogurt is often helpful. A diet low in roughage (fiber) may also be helpful.

Constipation may become a problem as children with MPS I get older, less active, and as the muscles weaken. If an increase in roughage in the diet does not help or is not possible, the doctor may prescribe laxatives or a disposable enema. Depending on the type of laxative used, side effects may include bloating, gas, abdominal cramps, or diarrhea. Side effects of enemas include rectal irritation or damage.

Tube feeding

Individuals with Hurler disease may have problems chewing and swallowing. If so, they are at risk of poor nutrition, choking, and aspiration. “Aspiration” means inhaling food or other substances into the lungs. Aspiration can lead to pneumonia, which may be life threatening.

A process called “tube feeding” can be used to help individuals with MPS I get the nutrition they need and protect them from choking or aspirating. It also makes it easier for a caregiver to feed the individual with MPS I. A flexible feeding tube is inserted that bypasses the mouth and throat and goes directly into the stomach or intestine. Nasogastric tubes (which are inserted through the nose) are usually a temporary measure lasting days to weeks. Longer-term feeding issues require surgical placement of a gastrostomy tube (G-tube) or jejunal tube (J-tube). Tube feeding is also called “enteral nutrition.”

Tube feeding
Courtesy of the National MPS Society