Abdominal Pain and Shunts

Abdominal Pain and Shunts – Not Always Related

Many people living with hydrocephalus and peritoneal shunts will experience abdominal pain or pressure at some point.  While it can feel alarming, this discomfort doesn’t always mean there’s a malfunction.

In many cases, the pain is related to normal abdominal issues unrelated to the shunt (such as constipation).  Other times, the body has reacted to the shunt tubing in the abdomen wall and created scar tissue that is the cause of the problem.

Understanding the types and causes of abdominal issues can help you talk confidently with your care team and find strategies that bring relief.

Types of Pain and Discomfort

It is important to define the pain or discomfort.

Focal pain or discomfort located at or very near the shunt insertion into the belly may be related to the tissues outside the belly cavity.

Generalized discomfort in the belly can have many causes.  It is important to discuss the quality of the pain and the location.

• How quickly has the discomfort or pain developed?
• Is the pain sharp or stabbing or dull and continuous?
• Does the discomfort come in waves and feel like cramping? Is the pain felt ‘inside’ the belly, is it very tender or easily aggravated (such as just having the belly be touched)?

Common Causes of Abdominal Pain and Pressure

The following are the most common causes of abdominal pain in patients with shunts:

1. Constipation

Constipation is one of the most common and overlooked causes of abdominal pain for people with VP shunts.  It can develop without any symptoms, it can show up with difficulty in passing a stool, or if it causes the bowel to distend, that can cause bloating, fullness or a cramping sharp pain.  It is often just a diffuse discomfort that is located more often on the left side of the abdomen.

When there is a lot of stool build up over a long time (days to weeks) it can increase your intra-abdominal pressure and might affect the function of a peritoneal shunt.  If this happens, this pressure will mimic or trigger shunt-related symptoms such as headaches, nausea, or a sense of increased brain pressure.  In these cases, effectively treating the constipation will treat the symptoms.

Maintaining regular, soft bowel movements can significantly reduce both abdominal discomfort and these symptoms that can overlap with a shunt malfunction.

2. Localized Tenderness around the shunt

Over time, the body naturally forms scar tissue (fibrosis) around the shunt catheter.  Normally shunt tubing will slide freely inside the scar and you will not feel the tubing.  Rarely, the scar tissue can attach to the shunt tubing and prevent that free motion and sliding.  Then normal body movement causes the tubing to pull on the adjacent tissues and that can cause localized/focal pain at the site of scarring.

(This is more commonly seen where the shunt tubing crosses the base of the skull, across the clavicle, or along the chest wall.  This can cause discomfort described as a soreness, tightness, or a tender feeling along the tubing, made worse with movement or touch).

Sometimes the scar at the entrance to the belly becomes quite thick or twisted, and movement will result in pain that is usually very localized to the area right around the scar.  Often that scar is distorted and seems to be ‘pulled’.

In all of these cases, the cerebrospinal fluid (CSF) continues to flow normally within the shunt.

The treatment usually requires a shunt surgery to reposition or replace the tubing in those areas, and the only goal is to resolve the pain.

3. Peritonitis – irritation of the abdominal lining (peritoneum)

The peritoneum — the inside thin lining of the abdominal cavity — can become painful if it is irritated.  The pain can be localized to one area, or generalized all around the belly.  It can be quite severe.

It is almost always is due to an infection.  In patients with peritoneal shunts, the most common cause of a peritoneal infection is after a surgical shunt revision; it can show up days to weeks after the surgery.

With peritonitis, the shunt is usually working but the inflammation can cause poor absorption of the CSF being deposited there by shunt.  The inflammation may cause the fluid to be walled off (‘pseudocyst’) causing discomfort or fullness but not much pain, and slowly developing signs of shunt malfunction.

4. Adhesions from Past Surgeries

Multiple intra-abdominal surgeries may lead to internal scar tissue forming between the organs and intestines – called adhesions. These fibrous bands can cause organs and tissues to stick together.  This can cause blockage of the intestines, or sometimes restrict the movement of the shunt catheter and forming trapped fluid and acting like a shunt obstruction.

These adhesions form weeks to years after the abdominal surgery and usually develop slowly – although a bowel obstruction they cause can show up suddenly.

5. Hernias

If there is a defect in the abdomen wall – by the belly button, in the groin (inguinal), or at the site of shunt tubing insertion, then the peritoneum can push through and be trapped causing pain.

These conditions are usually obvious to a physician, but may require imaging such as ultrasound or CT for diagnosis.  They are usually easily treated once identified.

Practical Tips for Managing Discomfort

• Prevent constipation: Eat fiber-rich foods, drink plenty of fluids, and use stool softeners or mild laxatives if recommended by your provider.
• Avoid straining: Try not to push during bowel movements or to lift heavy objects.
• Use gentle movement: If you have bloating or constipation, short walks and light stretching can help your bowels move.
• Try localized warmth: A heating pad or warm compress may soothe tight muscles or mild abdominal cramping.
• Wear comfortable clothing: Avoid tight waistbands that put pressure on the tubing path.
• Track your symptoms: Use the HydroAssist® mobile app to record when discomfort occurs — such as after meals, physical activity, or bowel movements — and share this information with your care team. Tracking patterns can help your doctor identify whether pain is related to shunt function, bowel changes, or normal tissue irritation.
• Ask about imaging: If pain persists, your doctor may suggest an ultrasound or CT scan to check for the issues listed above or to look for fluid buildup.
• Consider gentle physical therapy: Therapists familiar with post-surgical recovery may use soft-tissue techniques to reduce tension around the tubing.

Next Steps: Talking with Your Care Team

Open communication with your neurosurgeon or gastroenterologist is key. Describe where the pain is located, what it feels like, and what makes it better or worse. Sometimes simple adjustments, better bowel management, or reassurance that the shunt is functioning can ease anxiety and symptoms.

You know your body best. If something feels different or concerning, trust your instincts and reach out. You’re not alone in navigating this.

Learn More

Watch: Abdominal Pain and Shunt Irritation Discussion
Explore: Complications of Shunt Systems
Related Reading:

• Pseudocysts in Hydrocephalus: Causes, Symptoms, Treatment
• Shunt Malfunctions FAQ

Managing Abdominal Pain and Protecting Your Shunt Health

Abdominal pain or pressure related to a shunt can be frustrating, but it’s often manageable and not always a sign of malfunction. By understanding the common causes, staying proactive about constipation and pressure changes, and tracking when symptoms occur, you can help prevent flare-ups. Partnering closely with your neurosurgeon or gastroenterologist ensures you can find lasting relief and maintain confidence in your shunt health.

Information you can trust! This article was produced by the Hydrocephalus Association, copyright 2025. We would like to thank Bruce A. Kaufman, MD for his valuable contribution and expert input.

This article is designed to provide helpful information on the subjects discussed. It is not intended as a substitute for treatment advice from a medical professional. For diagnosis or treatment of any medical condition, consult your doctor.