What Is Ileus?

Ileus occurs when there’s a problem with motility — the process that moves waste through the digestive tract — in the small or large intestine (bowel).

How Normal Motility Works

Under normal conditions, muscles in the bowel walls contract in a coordinated rhythm to push waste along the digestive tract. These contractions are triggered by signals sent from nerves, which tell the muscles when and how to move. With ileus, motility slows down significantly or stops altogether. Because the muscles aren’t contracting properly, waste can’t move through the bowels and out of the body as it normally would.

This disruption can lead to:

• Abdominal discomfort or pain
• Bloating
• Nausea or vomiting
• Difficulty passing gas or stool

Why Treatment Matters

Because ileus prevents waste from moving through the digestive system, treatment is necessary to restore normal motility and relieve symptoms. Left unaddressed, it can lead to further complications, so it’s important to seek medical care if you suspect you have this condition. Tests to confirm ileus include CT scan, X-ray and blood tests.

Causes of Ileus

Ileus can develop for a variety of reasons, often related to recent surgery, infection, or other underlying health conditions. Common causes include:

• Abdominal surgery, which can temporarily disrupt normal bowel motility
• Certain infections, like peritonitis (an infection of the peritoneum, the lining of the abdomen)
• Injury to blood vessels that supply blood to the abdomen
• Electrolyte imbalance, such as low levels of sodium or potassium
• Certain medications, including strong pain medications like opioids
• Certain kidney or lung diseases
• Certain medical conditions, like cystic fibrosis

 Symptoms of Ileus

• Abdominal swelling or bloating
• Nausea and vomiting
• Abdominal cramps
• Loss of appetite
• Inability to keep food down
• Inability to pass stool or gas

Updated September 2026