How is Endometriosis Diagnosed?

Patient Presentation
A 16-year-old female came to clinic with a history of pelvic pain that was adversely affecting her daily activities. A couple days before menstruation she had constipation but during menstruation would have the pelvic pain associated with diarrhea and frequent urination. She intermittently took some ibuprofen with variable success. Some months she would need to miss school, but generally the pain would subside within 2 days of menses. Her menses were regular, lasting about 5 days but with heavy bleeding for the first couple of days. She also would have similar pains at other times that usually would last for < 24 hours, but would be associated with constipation and/or diarrhea. Again sometimes she would need to miss school or other activities. She denied any increased gas or bloating, dysuria, fever, or worsening with particular food. She denied any sexual activity and otherwise was doing well at school, in her activities and with friends. The pain could awaken her at night if it coincided with her menses but the non-menstrual associated pain would not awaken her at night. She says that she passed stools every 2 days and would occasionally clog the toilet or have harder stools. The family history was positive for a maternal aunt with endometriosis and her mother said she had painful periods as well but they did not cause functional problems.

The pertinent physical exam showed a healthy female with normal vital signs and growth parameters in the 50-75% range. Her general physical examination was normal. Her abdominal examination was soft, non-tender with no organomegaly but some noticeable stool burden in the lower left quadrant. Her musculoskeletal examination was normal. Genitourinary examination showed a Tanner V female for pubic hair with normal vulvar structures and intact hymen. Her anus was patent with normal anal wink. She declined a vaginal or rectal/abdominal examination.

The diagnosis of chronic constipation and dysmenorrhea seemed most likely. The mother and patient were very concerned about potential endometriosis and wanted a referral to a gynecologist. The pediatrician recommended that she be screened for alternative problems and for possible anemia given the heavier bleeding. She would begin with daily treatment for constipation using Miralax® and increased fiber. He also discussed menstrual hormone therapy but the family did not want to start anything until they had seen a gynecologist. He did recommend using ibuprofen starting before her periods and for the first couple of days until the pain seemed to subside. “It would also be very helpful to me and the gynecologist if you could keep a pain diary so we can look for patterns in your pain,” he explained. The laboratory testing that day included a complete blood count, inflammatory markers, complete metabolic profile and urinalysis and pregnancy testing which were all normal. When the patient saw the gynecoloogist about 6 weeks later, she reported much improved non-cyclical pain, but only some mild improvement with her last period using the ibuprofen. The gynecologist recommended to start hormonal suppression therapy and to followup. If the patient did not improve then they could consider potential laparoscopy. At followup 4 months later, the patient had had marked improvement with her pain overall, including one break through menstrual period that lasted only 2 days.

Endometriosis is classically defined as endometrial tissue occurring outside the uterine lining. It is a common cause of chronic pelvic pain and dysmenorrhea in adolescents. It can present differently in adolescents than adult women and usually can appear like many other common problems such as chronic constipation or gastrointestinal dysmotility. It is estimated that ~25-38% of adolescents with chronic pelvic pain have endometriosis. Use of clinical criteria versus laparoscopic documentation of disease makes the epidemiology of this problem more challenging.

The cause is not wholly agreed upon but many believe the idea of retrograde menstruation through the fallopian tubes with seeding of the peritoneal cavity, and with implantation and growth of the endometrial tissue as the cause. Yet, many women (up to 90%) can have retrograde menstruation, implying that other factors probably are involved and it is likely multifactorial. There are rare cases of premenarchal girls also being diagnosed with endometriosis. Adolescents present with pelvic pain that can be cyclic, acyclic or both with about 2/3s of adolescents presenting with both types of pain whereas adult women usually have cyclic pain. Other common symptoms include constipation, diarrhea, dysuria or urgency, dyspareunia in sexually active teens, and adolescents with endometriosis also have a higher migraine headache prevalence. Adolescents also report an inferior quality of life compared with normal teens.

Medical therapy usually starts with non-steroidal anti-inflammatory drugs and menstrual hormonal regulation using oral contraceptives including continuous hormonal suppression. Some patients may not respond to this treatment and may need laparoscopy and/or other therapy including hormonal or surgical therapies.

There is no cure for endometriosis but it can be managed. The nature history can include continued pain, fibrosis/adhesions, and infertility.

Chronic pelvic pain in adolescents includes:

  • Gynecological problems
    • Adnexal cysts – both functional and non-functional
    • Ovarian cysts
    • Endometrioma
    • Pelvic inflammatory disease
    • Reproductive tract anomies
  • Non-gynecological problems
    • Abuse and/or neglect
    • Abdominal/pelvic adhesions
    • Abdominal migraine
    • Celiac disease
    • Cystitis
    • Diabetic ketoacidosis
    • Food insensitivity/intolerance
    • Inguinal hernia
    • Irritable bowel syndrome
    • Inflammatory bowel syndrome
    • Musculoskeletal problems – back or pelvic bone or myofascial pain
    • Pancreatitis
    • Peptic ulcer disease
    • Pregnancy
    • Psychological stress – depression, anxiety
    • Sickle cell disease
    • Urolithiasis

Learning Point
History is one key to diagnosis of endometriosis. Pain diaries which document the frequency, duration, pain character, and alleviating/provoking factors are helpful. Physical examination to help with alternative diagnosis especially a reproductive tract anomaly or pelvic mass is also helpful. Pelvic examination is not always necessary, as a rectal-abdominal examination may yield as much information. Attention to the musculoskeletal system looking for bony tenderness, difficulties with spine or hip motion may indicate alternative problems. Laboratory testing usually looks for alternative diagnoses such as appendicitis, inflammatory bowel disease, cystitis etc. Pregnancy and sexually transmitted infection testing should also be considered. Imaging does not always need to be completed but ultrasound of the pelvis to assess for endometrioma, reproductive tract anomaly or ovarian cyst and/or adnexal torsion again can be helpful. Abdominal ultrasound could also be considered in the proper circumstances. Laproscopy is considered the standard but may or may not be used for diagnosis depending on the circumstances, and patients may be diagnosed clinically. When used it is usually intended to diagnose and for treatment. Laproscopy is commonly used if patients do not respond to a trial of medical therapy.

Questions for Further Discussion
1. What causes acute pelvic pain? A review can be found here
2. What causes constipation? A review can be found here
3. What are the ROME criteria used for? A review can be found here

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Constipation and Endometriosis.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Smorgick N, As-Sanie S. Pelvic Pain in Adolescents. Sem Reprod Med. 2018;36:116-122.

Shim JY, Laufer MR. Adolescent Endometriosis: An Update. J Pediatr Adolesc Gynecol. 2020;33(2):112-119. doi:10.1016/j.jpag.2019.11.011.

Lax Y, Singh A. Referred Abdominal Pain. Ped in Rev. 2020;41(8):430-433.

Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa