Long-term pain experienced in the lower abdomen and pelvis is a common condition that affects around 1 in 6 women. It is a very debilitating condition that has a marked effect on quality of life and day-to-day productivity. The direct and indirect health and socioeconomic costs due to chronic pelvic pain in the United States are estimated to be in excess of 39 billion dollars. The approach to this condition requires meticulous workup and an appreciation of the full breadth of causes for pain. It often requires involvement of health care professionals from multiple disciplines including gynaecologists, urologists, gastroenterologists, pain specialists, psychologists and physiotherapists.
What is chronic pelvic pain?
Chronic pelvic pain refers to pain in the lower abdomen or pelvis that has been present either intermittently or constantly for at least 6 months. Chronic pelvic pain is a very common condition that is seen by health care providers as often as migraine and lower back pain. It accounts for 1 in 10 visits to Gynaecology Outpatient Clinics and is the reason for performing 15-40% of laparoscopies and 12% of hysterectomies in the United States.
Chronic pelvic pain may lead to chronic pain syndrome in which normal daily function becomes impaired, sleep is disturbed and alteration in mood (e.g. depression) may occur.
What are the causes of pelvic pain?
A variety of gynaecological problems may be associated with pelvic pain.
- Endometriosis: Endometriosis is one of the leading gynaecological causes of pelvic pain. It may be associated with constant pain or with pain that is exacerbated during the periods (dysmenorrhoea). Pain may also occur during sex (dyspareunia) or when opening the bowels (dyschezia). For more information, see my section on Endometriosis.
- Adenomyosis: This refers to the invasion of womb lining tissue into the muscle of the wall of the womb. Adenomyosis is most often found in women who are in their thirties and forties and have had children.
- Scarring (Adhesions): Adhesions are “scar tissue” that may be caused by previous surgery, endometriosis or previous pelvic infection. Very fine adhesions are not thought to be a cause for pain. Dense adhesions that have a blood supply and which restrict free movement of structures such as bowel may be associated with pain.
- Pelvic inflammatory disease (PID): Studies indicate that chronic pelvic pain may occur in 18-33% of women after an episode of PID. PID is caused by sexually transmitted infections brought about by agents such as Chlamydia and Gonorrhoea. It is not clear exactly what causes pain once the acute inflammatory episode of PID is over but adhesions have been suggested as one cause.
- Ovarian cysts
- Pelvic congestion syndrome: This refers to swelling (or dilatation) of the pelvic veins.
- Fibroids: Typically, fibroids are thought to cause pain with periods (cyclical pain) and a feeling of pressure, rather than persistent pain throughout the cycle.
Problems with the urinary system:
- Bladder inflammation (Interstitial Cystitis): This is a common contributor to pelvic pain and often co-exists with endometriosis.
- Chronic urinary tract infections
- Bladder stones
Problems with the gut (gastrointestinal problems):
- Irritable Bowel Syndrome (IBS): As many as 50-80% of women with pelvic pain have symptoms suggestive of IBS. Pain associated with IBS may be cyclical as bowel symptoms worsen during menstruation in 50% of women.
- Inflammatory bowel disease
- Chronic constipation
- Chronic appendicitis: Around 20% of women with endometriosis also have appendiceal disease.
- Diverticular disease
- Chronic intermittent bowel obstruction
Problems with the musculoskeletal and/or nervous system:
- Myofascial pain and spasm of pelvic floor muscles: In one study of women who had had a normal laparoscopy, pain was related to a myofascial problem in 30% of cases. Pain arises from excessive muscle spasm that may produce a tight band of muscle in the pelvic floor.
A myofascial trigger point is a focus of excessive sensitivity located within the muscle or it’s covering tissue (known as fascia) that causes pain. Trigger points may occur in response to misalignment of the pelvic bones, injury to pelvic floor muscles, endometriosis, sleep disorders, fatigue and psychosocial stress.
- Nerve entrapment: Nerves may become trapped leading to pain. This pain is usually very localised over the area supplied by the nerve. Nerves may become trapped within scar tissue arising from previous operations. Nerve entrapment could also lead to the development of myofascial trigger points.
- Changes to the nervous system: The activity of nerves carrying pain sensations, or the perception of nervous impulses by the brain, may be altered in some women leading to an increased sensation of pain. Changes in nerve activity may be triggered by damage brought about, for instance, by surgery or infection. Pain due to changes in nerves is known as “neuropathic pain” and often produces pain that is burning or shooting in nature.
- Spinal disc problems
Pre-existing psychological issues can exacerbate pain. The converse is also often seen; pain brings on psychological problems that further intensifies the pain, leading to a vicious cycle.
- Anxiety and depression: Clinical depression develops in 25-50% of patients with chronic pain and if left untreated can be an obstacle to pain control.
- Sleep disturbance
- Sexual or physical abuse: 25-50% of women with chronic pelvic pain have abuse histories
- Substance abuse: Alcohol, narcotics or other drugs.
- Psychological stress related to marital problems or work.
How is Irritable Bowel Syndrome diagnosed?
There is no single test to definitively diagnose IBS.
However, symptom-based diagnosis of IBS can be made with a high degree of confidence using the Rome IV criteria. These criteria include abdominal pain lasting on average at least one day a week over the last three months and associated with at least two of the following factors:
- Pain and discomfort are related to having a bowel movement
- Altered frequency of passing stool
- Change in consistency of stool
Other symptoms that may be associated with IBS include the passage of mucus, straining to pass stool, urgency or a feeling of incomplete evacuation.
What can be done to find the cause of pelvic pain?
Because there is such a wide range of causes of pelvic pain, the particular tests performed should be carefully determined based on the features of the individual woman’s condition.
- Infection screening: Testing for sexually transmitted infections such as Chlamydia and Gonorrhoea in sexually active women
- Transvaginal ultrasound: This is helpful in diagnosing adenomyosis and fibroids as well as identifying endometriotic and other cysts. Ultrasound scanning will also help to determine whether there is restricted movement of pelvic structures such as ovaries and bowel, which could indicate the presence of adhesions.
- Magnetic resonance imaging (MRI): This could be particularly helpful when endometriosis is suspected to involve the bowel and for diagnosing adenomyosis.
- Laparoscopic surgery: Laparoscopy allows the pelvis to be thoroughly inspected. Chronic pelvic pain accounts for up to 40% of gynaecological laparoscopies. Laparoscopy can identify deposits of endometriosis that would otherwise remain undetected by tests such as ultrasound scans. Laparoscopy may also reveal adhesions and tethering of structures such as bowel or ovaries. 85% of abnormalities identified with laparoscopy involve endometriosis and adhesions. It is important to note, however, that laparoscopy does not guarantee that a problem will be found.
- Cystoscopy: This is helpful in diagnosing interstitial cystitis and can be performed at the same time as a laparoscopy. The distension brought about by instilling liquid into the bladder while performing cystoscopy produces symptom relief in 20-30% of patients.
How is chronic pelvic pain treated?
It is important to set realistic expectations regarding treatment outcome. For instance, it may not be possible to completely eliminate pain but if pain can be reduced and coping mechanisms can be improved, quality of life can be greatly enhanced. Hence, with chronic pain, a pivotal concept is that of managing pain rather than curing pain.
A wide range of treatment options may be required for pelvic pain depending on the underlying cause (or causes). Where necessary, it is important to involve other health care professionals in addition to the gynaecologist (e.g. pain specialists, physical therapists, urologists, gastroenterologists and psychologists) to effectively manage all aspects that may be associated with chronic pain.
Regular use of analgesics such as non-steroidal anti-inflammatory drugs (NSAIDs), paracetamol or co-dydramol may be helpful. Supervised use of the opioid group of analgesics (e.g. codeine, oxycodone and tramadol) may also be beneficial.
Treatments that suppress ovarian function have been shown to be very effective, especially when pain occurs in a cyclical pattern as in the case of painful periods (dysmenorrhoea). Options include the oral contraceptive pill, progesterone (e.g. provera and ralovera), danazol and GnRH agonists (e.g. buserelin, leuprolide and goserelin). Another hormonal treatment that may be effective is the Mirena intrauterine system, which is a progesterone-releasing intrauterine device (IUD). Hormonal treatments may be used in conjunction with laparoscopic surgery for treating endometriosis.
In some studies, endometriosis was found at laparoscopy in more than 30% of cases of chronic pelvic pain. Laparoscopic surgery is an effective approach for removing endometriotic deposits and any associated endometriotic cysts (or “chocolate cysts”).
Adhesions may be found in 25-50% of women with chronic pelvic pain but it is controversial whether they definitely cause pelvic pain. Laparoscopy is a highly effective approach for releasing adhesions that may be restricting the free movement of structures such as bowel.
Additional procedures aimed at reducing pain may be performed at the time of laparoscopy including presacral neurectomy, laparoscopic uterine nerve ablation (LUNA) and appendectomy.
Drugs targeting the nervous system:
Some drugs target pain pathways at the level of the spinal cord. These include gabapentin, carbamazepine, phenytoin and clonazepam.
Other treatments seek to inhibit pain more centrally. These include opiates and some drugs used for treating depression including paroxetine and amitriptyline.
Treatment for myofascial problems:
Myofascial trigger points may be injected using local anaesthetic agents (e.g. procaine and lidocaine) and botulinum toxin. Injection may be combined with percutaneous electrical stimulation via the inserted needle.
Physical therapy (or manual therapy) involves direct finger pressure, stretching and mobilization of fascia at sites where muscles are affected. This may be combined with the use of ultrasound and heat.
These treatments should be accompanied by a home exercise and stretching program.
Treatment for IBS:
This may involve dietary modifications such as inclusion of stool bulking agents and increasing intake of clear fluids. It may also be beneficial to avoid certain foods such as dairy products, cabbage, beans, grain, lactose, fructose and a group of carbohydrates called FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols). Around 40% of patients with IBS have lactose intolerance. Avoid caffeinated and carbonated products as they can cause bloating as can gum-chewing and smoking since they lead to more swallowing of air.
If pain is the predominant symptom, antispasmodic medications may be of benefit. Antispasmodics include mebeverine (e.g. Colofac), anticholinergics (e.g. Bentyl and Buscopan) and Peppermint oil. Peppermint oil also decreases abdominal distension and flatulence.
Long term use of stimulant laxatives is not recommended.
Treatment for interstitial cystitis:
Distension of the bladder at the time of cystoscopy may be beneficial in 20-30% of cases.
Pentosan polysulfate sodium (Elmiron) acts as a bladder protectant and may be helpful in around 30% of patients.
There are strong interactions between chronic pain and psychological problems. It is important to involve trained psychotherapists when needed in the assessment and management of chronic pelvic pain. Cognitive behavioural therapies are the treatment of choice for developing effective pain-coping strategies. Treatment of co-existing conditions such as depression is important for controlling pain.
Complementary and Alternative Medicine:
Transcutaneous Electrical Nerve Stimulation (TENS) may be beneficial for dysmenorrhoea.
Acupuncture, massage, physiotherapy, ultrasound and biofeedback training may benefit chronic pain.