Abdominal Adhesions: The Hidden Cause of Chronic Stomach Pain Nobody Talks About

There’s a particular kind of frustration that comes with abdominal pain that nobody can explain. The tests come back normal. The endoscopy shows nothing significant. The ultrasound is clear. And yet the pain keeps coming crampy, unpredictable, sometimes severe, often accompanied by bloating or changes in bowel habit that make daily life genuinely difficult.

For a significant number of people in this situation, particularly those who have had abdominal surgery in the past, the answer that keeps being missed is adhesions.

Adhesions are one of the most common complications of abdominal surgery worldwide. They cause a wide range of symptoms, from mild chronic discomfort to acute surgical emergencies. And yet they’re rarely discussed with patients before or after surgery in a way that prepares them for the possibility. People live with the consequences for years without knowing what’s causing their symptoms, because no standard investigation reliably shows adhesions, and because the connection between past surgery and present pain isn’t always made.

What Are Abdominal Adhesions?

Adhesions are bands or sheets of scar tissue that form between abdominal organs, or between an organ and the abdominal wall, after the lining of the abdominal cavity has been disturbed.

The inside of the abdominal cavity is lined with a smooth, slippery membrane called the peritoneum. Under normal conditions, the surfaces of abdominal organs slide freely against each other and against the abdominal wall the bowel moves, the stomach expands and contracts, organs shift slightly with posture and breathing, all without friction or restriction.

When the peritoneum is injured from surgery, infection, inflammation, or endometriosis, the normal healing response produces fibrin, a protein involved in clotting and repair. In most parts of the body, this fibrin is gradually broken down and reabsorbed as healing progresses. In the abdominal cavity, this process doesn’t always complete cleanly. Instead, the fibrin bridges between two adjacent surfaces, two loops of bowel, a loop of bowel and the abdominal wall, the bowel and a previous surgical scar and as it organises and matures, it becomes a permanent fibrous band.

That band is an adhesion. It tethers structures that should be able to move freely. And depending on where it forms, what it tethers, and how tight it becomes, it causes a range of problems from mild to severe.

What Causes Adhesions to Form?

Previous Abdominal Surgery

This is the most common cause by far. Almost any abdominal or pelvic surgery can cause adhesions appendectomy, caesarean section, hysterectomy, bowel surgery, hernia repair, gallbladder removal, and more. The more extensive the surgery, the more the peritoneum is disturbed, and the higher the risk of significant adhesion formation.

Studies suggest that adhesions form in the majority of patients who undergo open abdominal surgery some estimates put it at over 90 percent. Most of these adhesions are clinically silent, they exist without causing symptoms. But a significant proportion cause problems at some point, sometimes years or even decades after the original operation.

Laparoscopic surgery causes fewer and less extensive adhesions than open surgery, one of the advantages of the minimally invasive approach that’s less frequently discussed compared to the more obvious benefits of smaller scars and faster recovery.

Peritoneal Infection

Peritonitis infection of the abdominal lining, from a ruptured appendix, perforated bowel, or other source causes widespread inflammation of the peritoneum. As this inflammation heals, adhesions form. Patients who’ve had a peritoneal infection, particularly if it was severe or prolonged, are at high risk of developing clinically significant adhesions afterward.

Endometriosis

In women, endometriosis, where tissue similar to the uterine lining grows outside the uterus causes chronic inflammation of the pelvic peritoneum. Over time, this inflammation produces adhesions that can be dense and extensive, tethering the ovaries, fallopian tubes, bowel, and other pelvic structures to each other and to the pelvic walls. Endometriosis-related adhesions are a significant cause of chronic pelvic pain, bowel symptoms, and fertility problems.

Abdominal Radiation

Radiation therapy to the abdomen or pelvis for cancer treatment, damages the peritoneum and can cause adhesion formation alongside other effects on the bowel and surrounding tissues.

Inflammatory Bowel Disease

Crohn’s disease causes transmural inflammation, affecting the full thickness of the bowel wall which can lead to adhesions between adjacent loops of bowel, particularly in the areas most affected by disease.

How Do Adhesions Cause Symptoms?

The way adhesions cause problems depends on where they form and what structures they involve.

Chronic Abdominal Pain

The most common symptom. When adhesions tether bowel or other organs to the abdominal wall or to each other, normal movement is restricted. The bowel can’t move freely as it normally does during digestion and with changes in posture. When it’s pulled against its tethering adhesion by movement, distension, or peristaltic contractions, it causes pain.

This pain is typically crampy and intermittent rather than constant, it comes and goes depending on what the bowel is doing and how stretched the adhesion is at any given moment. It’s often poorly localised, the patient finds it hard to point to exactly where it hurts and it frequently doesn’t have an obvious trigger that makes sense from the outside.

The connection to previous surgery isn’t always made because the surgery might have been years or even decades ago. A patient who had an appendectomy at 25 and develops chronic right-sided abdominal pain at 40 may not immediately link the two.

Bloating and Digestive Disturbance

When adhesions involve the bowel, particularly the small intestine they can affect how the bowel moves and empties. Partial obstruction from adhesions causes gas and fluid to accumulate, producing bloating that can be significant and uncomfortable. Changes in bowel habit, alternating between constipation and looser stools are common.

These symptoms are frequently attributed to irritable bowel syndrome, which shares a very similar symptom profile, without adhesions being considered as a possible cause.

Small Bowel Obstruction

This is the most serious consequence of abdominal adhesions and the one that brings people to the emergency department. Adhesions are the most common cause of small bowel obstruction in adults, accounting for the majority of cases in patients who have had previous abdominal surgery.

When an adhesive band wraps around a loop of bowel, or when bowel becomes trapped in a space created by an adhesion, the bowel can become obstructed blocked. Contents can’t pass through, the bowel distends behind the blockage, and the patient develops:

• Crampy, colicky abdominal pain that comes in waves
• Distension, the abdomen becomes visibly swollen and tight
• Vomiting, initially of stomach contents, then bile, then increasingly foul-smelling material as the obstruction continues
• Inability to pass gas or stool
• High-pitched or absent bowel sounds

A partial obstruction may resolve with conservative management resting the bowel, intravenous fluids, nasogastric tube drainage. A complete obstruction that doesn’t resolve, or one where the bowel’s blood supply is compromised strangulation requires emergency surgery.

This is the acute presentation that brings adhesions into clinical view. The chronic symptoms the ongoing pain and bloating, often don’t get connected to adhesions until an acute obstruction episode makes the diagnosis unavoidable.

Fertility Problems in Women

Adhesions in the pelvis can involve the fallopian tubes and ovaries, distorting their anatomy, blocking the tubes, or preventing ovulation. Tubal adhesions are one of the recognised causes of female infertility and ectopic pregnancy. In women with a history of pelvic surgery, pelvic infection (such as from pelvic inflammatory disease), or endometriosis, adhesions should be considered when investigating unexplained infertility.

Urinary Symptoms

Adhesions involving the bladder or ureters particularly after pelvic surgery, can cause urinary symptoms including frequency, urgency, or difficulty with bladder emptying.

Why Are Adhesions So Often Missed?

This is the key question and the answer explains why so many people live with adhesion-related symptoms for years without a diagnosis.

Standard investigations don’t reliably show adhesions. Blood tests are normal. Ultrasound doesn’t image adhesions well. CT scanning can sometimes suggest adhesions, particularly when bowel obstruction is present, but doesn’t reliably show them in the absence of acute obstruction. Endoscopy looks at the inside of the bowel, not the outside where adhesions form.

The only way to definitively diagnose adhesions is to look directly inside the abdominal cavity either by laparoscopy or at open surgery. This means that for patients with chronic symptoms, the diagnosis often requires either a clinical judgment based on history and symptoms, no investigations to confirm it, just a pattern that fits or a diagnostic laparoscopy specifically to look.

The time gap between surgery and symptoms is confusing. When symptoms develop months or years after an operation, the connection isn’t obvious. Patients don’t mention the previous surgery because it seems too remote to be relevant. Clinicians focus on current symptoms and current investigations without asking about surgical history.

Symptoms overlap with more common conditions. Chronic abdominal pain, bloating, and changes in bowel habit are extremely common and are most often attributed to irritable bowel syndrome, functional bowel disorders, or dietary issues. These are diagnosed and managed without adhesions being considered and because treatment aimed at IBS doesn’t help adhesions, the symptoms continue.

How Are Adhesions Diagnosed and Managed?

Clinical Diagnosis

In many cases, the diagnosis is made clinically based on a pattern of symptoms in someone with a relevant surgical or gynaecological history. A patient with chronic crampy abdominal pain, bloating, and a history of appendectomy or caesarean section, in whom other investigations have been normal, has a presentation consistent with adhesion-related symptoms. The clinical picture points to the diagnosis even without confirmatory imaging.

This is an important point, a normal investigation result doesn’t rule out adhesions. It rules out other things. When other causes have been excluded and the clinical picture fits, adhesions become the most likely explanation.

Diagnostic Laparoscopy

When the diagnosis is uncertain, or when surgical treatment is being considered, a diagnostic laparoscopy, keyhole examination of the abdominal cavity, allows direct visualisation of adhesions. The surgeon can see where they are, which structures they involve, and how extensive they are. This information guides whether and how to proceed with treatment.

Managing Adhesion-Related Bowel Obstruction

For acute small bowel obstruction from adhesions, the initial management is non-surgical in most cases particularly for partial obstruction:

• Nil by mouth to rest the bowel
• Intravenous fluids to maintain hydration and electrolyte balance
• Nasogastric tube to decompress the stomach and relieve nausea and vomiting
• Close monitoring of clinical condition

Many partial adhesive obstructions resolve with this conservative approach within 24 to 48 hours as the bowel rests and the obstruction loosens.

Complete obstruction, obstruction that doesn’t resolve with conservative management, or any sign that bowel is ischemic, compromised blood supply, requires surgery. The adhesive band is divided and any compromised bowel is resected if necessary.

Adhesiolysis for Chronic Symptoms

For patients with chronic adhesion-related pain or recurrent partial obstructions, surgical division of adhesions adhesiolysis is an option. This is done laparoscopically where possible, the adhesive bands are carefully divided under direct vision, freeing the tethered structures.

The challenge with adhesiolysis is that the surgery itself, even laparoscopic surgery can cause new adhesions to form as part of the healing response. Dividing one set of adhesions can lead to new ones developing. This doesn’t mean adhesiolysis is futile, for many patients, it produces significant and lasting improvement in symptoms. But it means the decision to operate for chronic adhesion-related pain needs careful thought, and patient selection matters.

Adhesiolysis is most clearly indicated when:

• There have been multiple episodes of bowel obstruction requiring hospitalisation
• A specific adhesive band has been identified on imaging or laparoscopy that’s clearly responsible for symptoms
• Fertility is being compromised by pelvic adhesions
• Symptoms are severe and significantly affecting quality of life after other management options have been exhausted

Anti-Adhesion Barriers

During surgery, certain materials can be placed between raw surfaces to reduce the likelihood of adhesion formation. These anti-adhesion barriers, films or gels placed over areas where adhesions are most likely to form, degrade and are absorbed over time, but during the critical early healing period they physically separate adjacent surfaces and allow fibrin to be reabsorbed rather than forming permanent bonds.

These are used at the surgeon’s discretion during procedures known to carry high adhesion risk, bowel surgery, gynaecological surgery, and revision surgery in areas with pre-existing adhesions. They don’t eliminate adhesion risk entirely, but they reduce it.

Managing Symptoms Without Surgery

For patients who don’t meet the threshold for adhesiolysis, or who prefer not to have further surgery, symptom management focuses on:

Dietary modification – a low-residue or low-fibre diet reduces the bulk of intestinal contents and can reduce symptoms in patients with partial obstruction from adhesions. This is counterintuitive given that fibre is generally recommended for bowel health, but in the context of mechanical narrowing from adhesions, reducing the bulk that needs to pass through the narrowed segment reduces symptoms.

Managing bowel habit – avoiding constipation reduces the pressure inside the bowel and the risk of obstruction. Adequate hydration and stool softeners help keep stools soft enough to pass without straining.

Pain management – chronic adhesion-related pain is difficult to manage pharmacologically. Standard pain relief has limited effectiveness for this type of pain. A pain specialist or chronic pain service may be helpful for patients with significant ongoing pain that doesn’t respond to surgical management.

Awareness of warning signs – patients with known adhesions should know the symptoms of small bowel obstruction and understand that worsening crampy pain, distension, and inability to pass gas needs prompt medical attention rather than waiting at home.

What Should Patients With Previous Abdominal Surgery Know?

Anyone who has had abdominal or pelvic surgery, regardless of how long ago, should know that adhesions are a possibility when unexplained abdominal symptoms develop. This isn’t meant to cause alarm, most adhesions are silent and never cause problems. But when symptoms are present and investigations are normal, the surgical history matters and should always be mentioned.

When seeing a doctor for chronic abdominal pain, bloating, or bowel changes, sharing the full surgical history, including the type of procedure, when it was done, and any complications, gives the clinician the context needed to consider adhesions in the differential diagnosis.

Final Thoughts

Abdominal adhesions are common, frequently symptomatic, and consistently underdiagnosed, because they don’t show on the investigations that are routinely ordered, and because the connection between past surgery and current symptoms isn’t always made.

For people who have been living with unexplained abdominal pain, bloating, and digestive symptoms after previous abdominal surgery, adhesions are a diagnosis worth considering and discussing with a surgeon. It doesn’t always lead to further surgery, and conservative management helps many patients significantly. But knowing what’s causing the symptoms is the starting point for managing them properly.

Our surgical team evaluates chronic abdominal symptoms in the context of surgical history, considering adhesions where the clinical picture fits and advising on the most appropriate management for each individual situation. If you’ve had previous abdominal surgery and have been dealing with unexplained pain or bowel symptoms since, come in for a consultation. There may be a clearer answer than you’ve been given so far.