Endometriosis is one of the most common causes of pelvic adhesions, and the connection between the two conditions is direct. Adhesions are bands of fibrous scar tissue that cause organs and tissues to stick together, and they develop as a consequence of the chronic inflammation that endometriosis creates. In advanced cases, adhesions can affect up to 90% of patients and may involve multiple pelvic structures including the ovaries, fallopian tubes, bowel, and bladder.
How Endometriosis Creates Adhesions
Endometriosis involves tissue similar to the uterine lining growing in places it shouldn’t be, most often on pelvic surfaces, ovaries, and fallopian tubes. This misplaced tissue responds to hormonal cycles just like the lining inside your uterus, which means it bleeds with each menstrual cycle. But unlike a normal period, that blood has nowhere to go.
The repeated bleeding triggers a chain reaction. Each bleed generates a clotting response that produces thrombin, a protein involved in blood clot formation. That thrombin doesn’t just help with clotting. It also stimulates the endometriosis cells to grow further and releases a cascade of inflammatory molecules. Over time, this cycle of bleeding, clotting, and inflammation causes fibrin (a sticky protein involved in wound healing) to accumulate. The fibrin essentially glues nearby tissues together, forming the dense scar-like bands known as adhesions. The longer the cycle continues without treatment, the thicker and more established those adhesions become.
In severe cases, this process can create what clinicians call a “frozen pelvis,” where dense adhesions lock pelvic organs into fixed positions relative to each other.
Where Adhesions Typically Form
Adhesions tend to develop wherever endometriosis lesions are active, but some locations are more common than others. In one study of infertile women with endometriosis, the most frequent site was the adnexal area (the ovaries and fallopian tubes), affected in about 51% of cases. The anterior abdominal wall was the second most common location at roughly 24%, followed by the bladder and uterine surfaces.
Other commonly affected areas include the space behind the uterus (the cul-de-sac or pouch of Douglas), the ligaments supporting the uterus, and the rectovaginal septum, the thin wall between the rectum and vagina. When adhesions form in the cul-de-sac, they can completely seal off that space, a finding so significant in the clinical staging system that it alone can classify the disease as severe.
How Adhesion Pain Feels Different
Adhesion pain has a distinct quality that sets it apart from typical endometriosis pain. Rather than the deep, aching cramps associated with endometriosis lesions, adhesions often produce a pulling or tugging sensation inside the pelvis. This happens because the scar tissue physically restricts how your organs move. A sharp tug when you twist, bend, or change position can signal that adhesions are tethering structures that normally shift freely.
When adhesions involve the bowel, they can cause a range of digestive symptoms: chronic or intermittent bloating, abdominal cramping, nausea, early fullness after eating, and altered bowel habits that swing between constipation and loose stools. In more serious situations, adhesions can partially or completely obstruct the bowel, which causes escalating pain, vomiting, and an inability to pass gas or stool. Rectal bleeding and painful bowel movements during your period typically point to endometriosis directly affecting the colorectal area.
Impact on Fertility
Adhesions are a major reason endometriosis can make it harder to conceive. The mechanism is largely mechanical. Adhesions can restrict ovarian mobility, preventing the fallopian tube from positioning itself to capture a released egg. They can distort the normal relationship between the ovary and tube so significantly that even when ovulation happens normally, the egg simply can’t reach its destination. In severe cases, adhesions block the passage of both egg and sperm entirely, making natural conception impossible without intervention.
The staging system used to classify endometriosis severity reflects how central adhesions are to reproductive outcomes. The system assigns weighted points based on the size of endometriosis lesions and the density and location of adhesions on the ovaries, tubes, and peritoneum. Dense ovarian adhesions and tubal blockage receive high point values. Scores range from stage I (minimal, 1 to 5 points) through stage IV (extensive, more than 40 points), and the presence and severity of adhesions is often what pushes someone from a lower stage to a higher one.
Detecting Adhesions Without Surgery
Adhesions don’t show up on standard imaging the way cysts or tumors do, which has historically made them difficult to diagnose without surgery. However, a real-time ultrasound technique called the “sliding sign” has become a useful first-line tool. During a transvaginal ultrasound, the examiner applies gentle pressure to the cervix with the probe while using their other hand to press on the lower abdomen. They’re watching whether nearby organs, particularly the rectum and sigmoid colon, glide smoothly against the back of the uterus and cervix.
If the organs slide freely past each other, the sign is positive, meaning no adhesions are binding them together. If they don’t glide, and instead move as a single fixed unit, the sign is negative, indicating that adhesions have likely sealed those surfaces together. This technique is simple enough that it doesn’t require advanced ultrasound training, and it’s particularly good at predicting whether the cul-de-sac has been obliterated by scar tissue. It won’t catch every adhesion in every location, but it provides valuable information before any surgical decisions are made.
Surgery Can Treat and Cause Adhesions
Laparoscopic surgery is the primary way to physically remove adhesions, a procedure called adhesiolysis. The surgeon carefully separates organs and cuts away the scar tissue bands to restore normal anatomy and mobility. For many people, this brings significant pain relief and can improve fertility by freeing the tubes and ovaries. But there’s an uncomfortable paradox: the surgery itself can trigger new adhesion formation.
Post-operative adhesions are a well-recognized problem, affecting up to 90% of patients after endometriosis surgery. Even minimally invasive laparoscopic approaches lead to new adhesions in more than 80% of patients with severe disease and complete cul-de-sac obliteration. The body’s wound-healing response to surgical trauma follows the same inflammatory pathway that created the original adhesions.
To counter this, surgeons can place barrier materials between pelvic structures during the procedure. These barriers physically separate healing surfaces during the critical window when adhesions would otherwise form. One widely studied barrier made from oxidized regenerated cellulose reduced new adhesion formation by about 50% in laparoscopic procedures and cut the rate of re-formed adhesions (adhesions returning at previously treated sites) by roughly 83%. Another type of barrier material showed even greater reduction in new adhesion formation in a smaller trial. A gel-based barrier made from hyaluronate and carboxymethylcellulose also showed benefit in lowering adhesion scores after surgery. Not all barrier types perform equally, and the quality of evidence varies, but the overall picture supports their use as a meaningful preventive step during pelvic surgery.
The Cycle of Inflammation and Scarring
What makes endometriosis-related adhesions particularly challenging is their self-reinforcing nature. The endometriosis lesions bleed, which triggers inflammation, which produces adhesions, which restrict organ movement and trap more inflammatory fluid near the lesions, which fuels further inflammation and more adhesion formation. Hormonal treatment that suppresses the menstrual cycle can slow this process by reducing the cyclical bleeding that drives it, but it won’t dissolve adhesions that have already formed. Only surgical removal can do that, and as noted, surgery carries its own risk of creating new ones.
This is why early identification matters. The less time the inflammatory cycle runs unchecked, the less extensive the adhesion burden tends to be. For people experiencing pelvic pain with a pulling quality, digestive symptoms that worsen around menstruation, or unexplained difficulty conceiving, adhesions from endometriosis are a possibility worth investigating, particularly with accessible tools like the sliding sign ultrasound technique now available.