Adhesions (Internal Scar Tissue)

How adhesions form

Surfaces inside the abdomen are covered with a slippery lining (peritoneum) that lets organs slide over one another. When this lining is injured by surgery, infection, inflammation, blood or foreign material, the body lays down fibrin to heal it. Normally this is broken down within days. If it is not, fibroblasts and blood vessels grow into it, forming permanent bands that tether organs to each other or to the abdominal wall.

Adhesions can be thin, filmy strands or thick, dense bands. They can also form in other places: inside the uterus, around the ovaries and tubes, between the lungs and chest wall, and in joints such as the shoulder (frozen shoulder is sometimes called adhesive capsulitis).

Causes and risk factors

• Abdominal and pelvic surgery: the leading cause. Open surgery causes more adhesions than keyhole (laparoscopic) surgery. Bowel, gynecologic and repeated operations carry the highest risk.
• Infection and inflammation: appendicitis, peritonitis, pelvic inflammatory disease and Crohn's disease.
• Endometriosis: tissue similar to the uterine lining bleeds and inflames the pelvis, creating dense adhesions.
• Radiation therapy to the abdomen or pelvis.
• Uterine procedures: D&C, especially after miscarriage or delivery, can cause adhesions inside the uterus (Asherman's syndrome).
• Peritoneal dialysis and some medicines, rarely.

Symptoms

Most adhesions cause no symptoms. When they do:

Bowel obstruction

Adhesions are the most common cause of small bowel obstruction in adults in Western countries. A loop of bowel kinks or twists around a band. Symptoms include cramping pain in waves, bloating, nausea and vomiting, and inability to pass gas or stool. If the blood supply is cut off (strangulation), pain becomes constant and severe, which is a surgical emergency. See adhesive small bowel obstruction.

Chronic abdominal or pelvic pain

Adhesions may cause pulling or aching pain, sometimes worse with movement, exercise, bowel movements or sex. The link between adhesions and chronic pain is debated, because many people with extensive adhesions have no pain.

Infertility

Pelvic adhesions can distort or block the fallopian tubes or trap the ovaries, preventing egg and sperm from meeting. Adhesions inside the uterus can cause light or absent periods, recurrent miscarriage and infertility.

Diagnosis

Adhesions are hard to see on standard scans. Diagnosis depends on the problem:

• Bowel obstruction: CT scan shows dilated bowel loops and a transition point without another cause, such as a hernia or tumor.
• Chronic pain: diagnosis is by excluding other causes. Laparoscopy can confirm adhesions directly.
• Infertility: an X-ray dye test of the tubes (hysterosalpingogram), saline ultrasound or hysteroscopy for uterine adhesions, and laparoscopy for pelvic adhesions.

Treatment

No symptoms

No treatment is needed.

Adhesive bowel obstruction

Many partial obstructions settle without surgery. Treatment in hospital includes:

• nothing by mouth, intravenous fluids, and a tube through the nose to drain the stomach
• a water-soluble contrast drink (such as Gastrografin) that both predicts and helps resolve obstruction
• surgery (adhesiolysis) if the obstruction does not resolve within about 3 days, or immediately if strangulation is suspected

Chronic pain

Treatment may include pain management, physical therapy, and treating co-existing conditions such as endometriosis or irritable bowel syndrome. Laparoscopic adhesiolysis helps some people, but results are mixed, and surgery itself can create new adhesions.

Infertility

Laparoscopic surgery can free tubes and ovaries. Hysteroscopic surgery removes adhesions inside the uterus. In vitro fertilization (IVF) is often recommended when tubes are badly damaged.

Prevention

Surgeons reduce adhesion risk by using laparoscopic techniques when possible, handling tissue gently, controlling bleeding, and sometimes placing absorbable barrier films or gels at the end of surgery. Treating pelvic infections promptly and managing endometriosis also help.

Frequently asked questions

What are adhesions?

Adhesions are bands of scar tissue that join organs or tissues together inside the body. They usually form after abdominal or pelvic surgery, infection or endometriosis. Most cause no symptoms, but some lead to pain, bowel obstruction or infertility.

What does adhesion pain feel like?

People describe a pulling, tugging, aching or sharp pain in one area, sometimes worse when stretching, exercising or having a bowel movement. Cramping pain with bloating and vomiting suggests the adhesions are blocking the bowel, which needs urgent care.

Can adhesions go away on their own?

Established adhesions do not dissolve on their own. However, many never cause symptoms, and some partial bowel obstructions caused by adhesions resolve without surgery. Surgery can cut adhesions, but they may reform.

Can adhesions show up on an ultrasound or CT scan?

Usually not directly. Scans show their effects, such as a blocked bowel or fluid-filled tubes. Specialized ultrasound can sometimes show whether organs slide normally. Laparoscopy is the most reliable way to see adhesions.

How long after surgery can adhesions cause problems?

Adhesions form within days to weeks after surgery, but problems can appear at any time, from weeks to decades later. Adhesive bowel obstruction can occur many years after an operation such as an appendectomy or cesarean section.