Dilated Small Bowel Loops on X-ray

Dilated small bowel loops are wider than normal. There are many causes of dilated small bowel loops. Some of the causes may make you sick while others may be more chronic or even asymptomatic.

What is the small bowel?

The small bowel or intestine is responsible for digestion and absorption of food. It is a long series of loops or pipes as long as 25 feet long. The small intestine is positioned between the stomach and colon.

What do dilated small bowel loops  look like on X-ray?

X-rays are a common starting point to investigate symptoms such as pain in your abdomen.   X-rays of the abdomen will show the intestines, but only if they have gas within.

The loops of small intestine are often not seen on X-ray if they are filled with fluid and ingested food. In these cases, they will blend with the rest of the abdomen and be invisible.  Dilated small bowel loops will be greater than 3.0 cm.

Dilated small bowel loops meaning

When the small bowel loops are visible, they may appear dilated or wider than usual to the radiologist who interprets the x ray.

The radiologist will look at the pattern of dilation and try to determine the cause. The most worrisome is a small bowel obstruction. This happens when the a segment of the intestine gets blocked, either partially or completely.

Symptoms of dilated small bowel loops

Symptoms depend on the underlying cause.  Some patients may have no symptoms when the cause is something benign.  Other patients can be extremely sick with nausea, vomiting and pain when the intestine is blocked.

What causes dilated small bowel loops?

Small bowel obstruction

One of the more common causes for dilated small bowel loops is a small bowel obstruction or blockage.  One of the most common causes for small bowel obstruction is when you develop adhesions or scar tissue after surgery.

Often patients with small bowel obstruction are sick with pain and vomiting. A surgeon will often get involved in your care. The X-ray will show big dilated small bowel loops with air fluid levels.

Ileus

Another common cause is called adynamic ileus which is basically a paralyzed intestine which does not propel contents.

This can be due to multiple causes such as: drugs, infections/sepsis, surgery, metabolic disturbances, and intestine which is starved of blood supply (intestinal ischemia).

The X-ray will show dilated loops of small intestine throughout also with air fluid levels. Often the X-ray appearance will overlap with that of obstruction of the intestine. Additional imaging studies like CT may be ordered to help exclude an obstruction.

Normal variation

Dilated small bowel loops do not always indicate a problem. Increased intestinal gas and dilation can simply be related to drinking a carbonated drink.  Many patients may have scattered dilated small bowel loops on X-ray which are not necessarily concerning.

Hernias

Less common causes of blockages of the intestines can include a hernia. A segment of the intestine may go into a hernia where it causes an obstruction. This is a mechanical obstruction, meaning it must be corrected by surgery in order to allow fluid and food to get through.

Crohn’s disease

Other less common causes include bowel inflammation such as Crohn’s disease. The inflamed intestine in this condition can become narrowed or scarred and cause a blockage.

Cancer

A growth or cancer of the small bowel can cause obstruction.

Bleeding

Bleeding into the wall of the intestine can cause a blockage. This can occur from trauma or when your on blood thinners for other conditions.

Are dilated small bowel loops   dangerous? (or cancerous)

They can be at times depending on the cause.  A small bowel obstruction can be dangerous and needs to be promptly treated.  A small bowel obstruction can sometimes be caused by cancer.

Dilated small bowel loops treatment

The treatment will depend on the underlying cause.   For example, the underlying cause of ileus will need to be treated for it to get better.  A drug that is causing ileus will need to be discontinued.

Small bowel obstructions are often managed by a surgeon.  A small bowel obstruction may need surgery.

Dilated small bowel loops on X-ray : summary

There are a wide variety of conditions that can cause dilated small bowel loops on X-ray.  These can range from normal variation all the way to life threatening conditions such as obstruction.

The appearance on X-ray and the clinical information will be important for a correct diagnosis.  Further imaging with CT scans may also be needed.  Surgical consultation will often be obtained when there is a small bowel obstruction.