What are the common causes of dysuria, green or yellow discharge, and abdominal pain, possibly indicating a sexually transmitted infection (STI) such as gonorrhea or chlamydia?

Infections Causing Burning with Urination, Green Discharge, and Abdominal Pain

The most common infections causing this triad of symptoms are gonorrhea (Neisseria gonorrhoeae) and chlamydia (Chlamydia trachomatis), which frequently co-occur and require dual empiric treatment with ceftriaxone 250 mg IM plus doxycycline 100 mg orally twice daily for 7 days. 1, 2, 3

Primary Causative Organisms

Gonorrhea (Neisseria gonorrhoeae):

• Causes purulent or mucopurulent discharge that is typically yellow-green in color 4, 1
• Presents with dysuria (burning with urination) in both men and women 1, 2
• Can ascend to cause pelvic inflammatory disease (PID) in women, manifesting as abdominal pain 5
• Approximately 53-100% of extragenital infections are asymptomatic, but symptomatic cases present with these classic findings 6

Chlamydia (Chlamydia trachomatis):

• Frequently causes mucopurulent cervicitis in women with yellow endocervical discharge 4, 1
• Produces urethritis with dysuria in both sexes 1, 2
• A leading cause of PID when untreated, resulting in lower abdominal pain 5, 1
• Approximately 77% of chlamydial infections are asymptomatic, but symptomatic cases present with these findings 7

Additional Organisms to Consider

Trichomonas vaginalis:

• Can cause dysuria, discharge, and occasionally abdominal discomfort 1, 6
• Should be tested for in persistent or recurrent cases 1

Mycoplasma genitalium:

• Emerging cause of urethritis and cervicitis with similar symptoms 1, 2
• Responds better to azithromycin than doxycycline 1, 8

Diagnostic Approach

Essential testing includes:

• Nucleic acid amplification tests (NAATs) for both gonorrhea and chlamydia, which have 86.1-100% sensitivity and 97.1-100% specificity 6, 9
• Testing can be performed on first-void urine, urethral swabs, or endocervical specimens 1, 2
• Syphilis serology and HIV testing should be performed concurrently 1, 3

Clinical findings that support STI diagnosis:

• Mucopurulent or purulent discharge visible on examination 1, 2
• Cervical motion tenderness or uterine/adnexal tenderness (suggesting PID) 5
• Pyuria on urinalysis (≥10 WBC per high-power field) 2, 10

Critical Pitfall: UTI Misdiagnosis

A major diagnostic error is misdiagnosing STIs as urinary tract infections:

• In one ED study, 64% of women with untreated STIs were incorrectly diagnosed with UTI instead 11
• Abnormal urinalysis findings (pyuria, leukocyte esterase) occur in 92% of women with genitourinary symptoms but have only 41% positive predictive value for true UTI 11
• The presence of vaginal discharge, cervical discharge, or abdominal pain should prompt STI testing rather than assuming UTI 10, 11

Recommended Treatment Regimen

Empiric dual therapy should be initiated immediately without waiting for test results: 1, 2, 3

For gonorrhea coverage:

• Ceftriaxone 250 mg intramuscularly as a single dose 3, 12

For chlamydia coverage:

• Doxycycline 100 mg orally twice daily for 7 days (preferred) 1, 2, 3
• OR Azithromycin 1 g orally as a single dose (alternative, better for M. genitalium) 1, 2, 13

When to treat empirically:

• High-risk patients unlikely to return for follow-up 1, 3
• Settings where gonorrhea or chlamydia prevalence exceeds 5-15% 14, 1
• Presence of mucopurulent discharge or objective signs of urethritis/cervicitis 1, 2

Management of Pelvic Inflammatory Disease

If abdominal pain is present with cervical motion tenderness or uterine/adnexal tenderness, treat for PID: 5

• This represents ascending infection requiring broader antimicrobial coverage
• Hospitalization should be considered for severe pain, fever, or inability to tolerate oral therapy 5
• PID can cause permanent reproductive damage even with mild symptoms, so maintain a low threshold for diagnosis 5

Partner Management (Non-Negotiable)

All sexual partners within the preceding 60 days must be evaluated and treated: 1, 3

• Partners should receive the same dual therapy regimen regardless of symptoms 4, 3
• Patient must abstain from sexual intercourse for 7 days after initiating therapy AND until all partners complete treatment 1, 2, 3
• Failure to treat partners is the primary cause of reinfection 1

Follow-Up Protocol

Patients should return if: 1, 2, 8

• Symptoms persist or recur after completing therapy
• New symptoms develop

Repeat testing at 3-6 months is recommended due to high reinfection rates 3, 8

For persistent symptoms after treatment:

• Confirm objective signs of inflammation before retreating 1, 2
• Consider Trichomonas vaginalis testing if not previously done 1
• Consider metronidazole 2 g orally single dose plus azithromycin 1 g orally single dose (if not used initially) 1