Ileus: Symptoms, Causes, and Treatment

A Common Condition That Occurs After Abdominal Surgery

Peristalsis / Getty Images

Ileus is a condition that occurs when the natural motion of the intestine that moves material along, called peristalsis, is slowed down or stopped.

When food stops moving along, it can build-up to the point where it is blocking the intestine, like a clog in a pipe. If too much food or material gets caught in the blockage, it can lead to serious and even life-threatening complications. An ileus requires treatment and depending on the seriousness of the situation, it could include anything from changing the diet to surgery.


An ileus can occur for a variety of reasons, including having recent abdominal surgery and having a disease or condition of the digestive tract.


During abdominal surgery, anesthetics and painkillers are often used to manage discomfort. This is appropriate medical care to manage pain during and after an operation but these medications (especially narcotics) can have the side effect of slowing down the digestive process. After surgery, ileus is normal and patients are monitored closely to ensure that it resolves. Patients are only given something to eat when the bowel seems ready and the muscles can move the food along again. 


Some of the common medications that are associated with the risk of ileus include:

  • Dilaudid (dihydromorphinone, hydromorphone)
  • Morphine (MScontin, Oramorph, Sevredol)
  • Oxycodone (Percocet, OxyContin)
  • Tricyclic antidepressants (amitriptyline, imipramine [Tofranil])

Diseases and Conditions

There are several conditions that are associated with an increased risk of developing an ileus. In Crohn’s disease, inflammation can create scar tissue in the intestine, which in turn causes a thickening in the walls of the intestine and can lead to ileus. Parkinson’s disease is a neurological disorder and may affect the nerves that control peristalsis, causing an ileus.

The conditions that can be associated with ileus are:

Ileus in Children

In children, a condition where the bowel slides in on itself like a collapsing telescope, called intussusception, can cause an ileus.


Most ileus symptoms occur in the digestive system. When material and gas aren’t passed, they build up and that can cause bloating and distention. Outwardly, the abdomen might look full and swollen. The symptoms of ileus may include:

Risk Factors

The biggest risk factor for ileus is having abdominal surgery. When it comes to the complications for which people come back to the hospital and are admitted again shortly after having abdominal surgery, ileus is the second most common.

Older adults may especially be at risk because they tend to receive more medications and may have other risk factors also. Some of the other risk factors for developing an ileus include:

  • Crohn’s disease
  • Diverticulitis
  • Injury to the intestines
  • Electrolyte imbalances
  • Peripheral artery disease (lack of blood flow to the limbs)
  • Receiving radiation treatment in the abdominal area
  • Recent abdominal surgery
  • Sepsis
  • Sudden extreme weight loss


A physician may use a physical exam and one or more different imaging tests to diagnose an ileus.

Physical Exam and History

When there is a history of recent abdominal surgery or some of the other risk factors, as well as symptoms, a physician may suspect an ileus. A careful history will include asking about medications as well as any other diagnosed conditions, whether or not they’re related to digestion.

A physical exam will include a look at the abdomen to see if it is swollen or distended. A normally functioning bowel will make certain sounds that can be heard with a stethoscope. An ileus may cause either a lack of healthy bowel sounds or an excess of them that can be heard through the stethoscope. 


A plain X-ray of the abdomen may show certain characteristics of an ileus such as excess gas or an obstruction. This is usually the first test done when diagnosing a possible ileus. This test is helpful in quickly looking for patterns of gas in the bowel that can help doctors make a prompt diagnosis of ileus in some patients. A patient will lie on a table and an X-ray machine will be positioned over the abdomen to take the images.

CT (Computed Tomography) Scan

A CT scan is a type of X-ray that provides a cross-sectional view of the abdomen. Patients lie on an exam table that slides into a hole in the middle of the CT machine in order for images of the abdomen to be captured. Contrast dye is usually given through an IV so that the structures in the abdomen can be seen more clearly. This test may help in finding the location of the ileus.


In many cases, the treatment will depend on the seriousness of the ileus and if the lack of peristalsis has resulted in creating a partial or complete obstruction. In a partial obstruction, some material may be still passing through the bowel, but in a complete obstruction, nothing can get through.

Paralytic Ileus

To effectively treat an ileus, it is helpful to understand any underlying causes. An ileus is treated in the hospital, especially when necessary to receive fluids by IV. When a medication is suspected of causing the ileus, discontinuing it and/or switching to another drug may be the first step.

Other medications that speed up the bowel (increase motility) might be given to counteract the lack of peristalsis that's causing the ileus. A nasogastric (NG) tube may be placed into the nose and down into the stomach to release pressure in the bowel and to remove gas or fluids and stop vomiting. If the ileus is occurring after abdominal surgery, it may resolve in two to four days without additional surgery. If there is an obstruction caused by the ileus, other treatments may also be necessary.


In some cases, preventing an ileus is not possible because it occurs after abdominal surgery or as a result of a related digestive condition. Prevention methods that may help include minimizing the use of surgery, decrease the use of narcotics after surgery, and letting the surgeon and other medical staff know about having an ileus in the past. Minimizing the use of narcotics after surgery, knowing the risk factors and the symptoms of ileus can help in identifying one quickly and therefore seek medical attention right away for a better chance at an uneventful resolution.

A Word From Verywell

After surgery, physicians will monitor the bowel to ensure that it has started working well again before giving any food, which can help prevent complications if there is an ileus. Ileus is a common condition, especially after abdominal surgery, and most people recover well without any complications. Even if surgery to remove part of the bowel is necessary, the intestines are long and losing a small part will not usually have an impact on digestion. Early diagnosis and treatment of an ileus will offer the best chance of a full recovery without any further complications. 

Frequently Asked Questions

  • Is there a difference between an ileus and a paralytic ileus?

    No, there is no difference between an ileus and a paralytic ileus. Both terms describe a condition in which the flow of intestinal contents is slowed or stopped.

  • What is the difference between an ileus and bowel obstruction?

    Ileus is a problem with peristalsis, the intestine's natural movements to push food through the digestive tract. If enough food accumulates in the intestine, it can cause a blockage.

    On the other hand, a bowel obstruction is caused by a physical blockage, such as a hernia, that prevents the passage of intestinal contents.

  • What causes a postoperative ileus?

    Postoperative ileus is a side effect caused by the medications and painkillers used during surgery. These medications can slow down or even stop peristalsis for a time after the procedure.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Vilz TO, Stoffels B, Strassburg C, Schild HH, Kalff JC. Ileus in Adults. Dtsch Arztebl Int. 2017;114(29-30):508–518. doi:10.3238/arztebl.2017.0508

  2. Zeinali F, Stulberg JJ, Delaney CP. Pharmacological management of postoperative ileus. Can J Surg. 2009;52(2):153–157. PMID: 19399212

  3. Carroll J, Alavi K. Pathogenesis and management of postoperative ileus. Clin Colon Rectal Surg. 2009;22(1):47–50. doi:10.1055/s-0029-1202886

  4. Beach EC, De Jesus O. Ileus. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID:32644363.

Additional Reading
  • National Institutes of Health. "Intestinal pseudo-obstruction." National Institute of Diabetes and Digestive and Kidney Diseases. Feb 2014.

  • Nghia, "Jack" Vo, MD, et al. Intussusception in children. UpToDate. Aug 27, 2019.

  • Ansari P. “Ileus." Merck Manual Professional Version. Jan 2017.

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.