An adhesion is a band of scar-like tissue that forms between internal organs or tissues that aren’t normally connected. These fibrous bands can stick organs together, tether them to the abdominal wall, or create kinks in the intestines. Adhesions develop most often after surgery, with 67% to 97% of patients developing them after major abdominal procedures.
How Adhesions Form
When tissue inside your body is injured, whether by a surgeon’s scalpel, an infection, or inflammation, your body launches a repair process. Part of that process involves creating a sticky gel made of a protein called fibrin, which acts like biological glue to seal the wound. Normally, your body breaks down this fibrin once healing is complete. But when that breakdown process is incomplete, the temporary fibrin scaffolding becomes permanent. Connective tissue cells, blood vessels, and even nerve fibers grow into the fibrin matrix, turning it into a tough, rope-like band of scar tissue.
This is why adhesions can cause pain: they literally have nerves running through them. And because they physically connect structures that should move independently, they can restrict the normal sliding and shifting of organs inside your abdomen.
What Causes Them
Surgery is the dominant cause. Roughly 75% of diagnosed adhesions trace back to an abdominal procedure, and open surgery (where a large incision is made) leads to adhesions in more than 90% of cases. Colorectal surgery carries the highest risk among general abdominal procedures, while ovarian surgery has the highest adhesion-related readmission rate among gynecological operations (about 7.5 readmissions per 100 surgeries). Having three or more prior abdominal surgeries dramatically increases the risk of both adhesions and complications from them.
Surgery isn’t the only trigger. Any source of inflammation inside the abdomen or pelvis can set off the same process:
- Infections in the abdomen or pelvis, including pelvic inflammatory disease
- Inflammatory bowel conditions like Crohn’s disease or diverticulitis
- Endometriosis
- Appendicitis
- Radiation therapy to the abdomen
- Peritoneal dialysis for kidney failure
Where They Develop
Adhesions can form almost anywhere inside the body, but they’re most common in the abdomen and pelvis. They frequently involve the bowel, the reproductive organs (ovaries and fallopian tubes), the area around the heart, the spine, and the hand. The location matters because it determines what symptoms you experience and what complications are possible.
In the pelvis, adhesions can bind the fallopian tubes or ovaries to surrounding tissue, distorting their normal anatomy. Up to 90% of women develop adhesions following major gynecological surgery, and pelvic adhesions account for an estimated 15% to 20% of all secondary female infertility cases. They’re also a common cause of chronic pelvic pain and painful intercourse.
In the abdomen, adhesions most often involve the small intestine. When scar bands kink or compress a section of bowel, they can partially or completely block it, a condition called adhesive small bowel obstruction. This is the most serious complication of abdominal adhesions and often requires emergency care.
Symptoms to Recognize
Many adhesions cause no symptoms at all. You can have extensive internal scarring and never know it. Problems arise when adhesions pull on organs, restrict their movement, or create blockages.
The most common symptoms depend on location. Abdominal adhesions can cause cramping pain, bloating, nausea, and changes in bowel habits. If a bowel obstruction develops, the pain becomes more severe and is typically accompanied by vomiting, inability to pass gas, and a visibly swollen abdomen. Pelvic adhesions often present as chronic pelvic pain, pain during intercourse, or difficulty getting pregnant. For many women, these symptoms carry a significant emotional burden as well, affecting self-esteem and quality of life.
Why They’re Hard to Diagnose
Adhesions are notoriously difficult to detect without surgery. Standard imaging like X-rays and basic CT scans often miss them entirely because the fibrous bands look similar to surrounding soft tissue. The gold standard for diagnosis is direct visualization during surgery, where the surgeon can actually see and feel the adhesions.
That said, newer imaging techniques are improving. Abdominal ultrasound, when performed by an experienced radiologist specifically looking for adhesions, has shown about 91% sensitivity and 88% diagnostic accuracy. A specialized form of MRI that captures organ movement in real time (called cine MRI) performs similarly, with about 92% diagnostic accuracy. Cine MRI is particularly good at detecting adhesions between internal organs, while ultrasound works well for adhesions attached to the abdominal wall. In practice, though, most adhesions are discovered incidentally during surgery for another issue, or they’re suspected based on symptoms and a history of prior abdominal surgery.
Treatment Options
The only way to physically remove adhesions is surgery, a procedure called adhesiolysis. This can be done through open surgery or laparoscopically (using small incisions and a camera). The paradox is obvious: the treatment for scar tissue caused by surgery is more surgery, which can create new scar tissue.
Research bears this out. One study comparing outcomes found that the overall recurrence rate of symptoms after laparoscopic adhesiolysis was about 11.5%, and patients who had three or more prior surgeries were over seven times more likely to have symptoms return. Laparoscopic surgery for bowel obstruction caused by adhesions didn’t reduce the likelihood of recurrence compared to other approaches, and in some cases was associated with a higher rate of needing additional operations.
For this reason, surgery for adhesions is generally reserved for cases where the benefits clearly outweigh the risks: bowel obstructions, significant infertility, or chronic pain that hasn’t responded to other management. Many people with symptomatic adhesions manage with physical therapy, pain management, dietary adjustments (smaller, more frequent meals and avoiding high-fiber foods that are harder to push through a partially narrowed bowel), and careful monitoring.
Preventing Adhesions During Surgery
Surgeons have several strategies to reduce adhesion formation during abdominal and pelvic procedures. Minimally invasive surgery (laparoscopy) causes less tissue trauma than open surgery, which translates to fewer adhesions. Careful surgical technique, keeping tissues moist, minimizing contact with foreign materials like talc from gloves, and gentle handling of organs all help.
Barrier products are another tool. These are thin films, gels, or liquid solutions placed between tissues at the end of surgery to physically separate healing surfaces during the critical window when fibrin bridges would otherwise form. Several types are commercially available, made from materials like plant-based cellulose, hyaluronic acid, and synthetic polymers. They dissolve on their own over days to weeks, by which time the tissue surfaces have healed independently. These barriers reduce adhesion formation, though they don’t eliminate it entirely, and they’re typically used in surgeries where the adhesion risk is highest, such as open gynecological or colorectal procedures.