What are the differential diagnoses for a patient presenting with lower abdominal pain and white discharge?

Differential Diagnosis for Lower Abdominal Pain with White Discharge

In sexually active women presenting with lower abdominal pain and white vaginal discharge, pelvic inflammatory disease (PID) should be the primary diagnostic consideration and empiric treatment should be initiated immediately if cervical motion tenderness, uterine tenderness, or adnexal tenderness is present on examination. 1

Primary Gynecologic Considerations

Pelvic Inflammatory Disease (PID)

• PID is the most critical diagnosis to consider in sexually active women with lower abdominal pain and vaginal discharge, as delayed treatment leads to serious sequelae including infertility, ectopic pregnancy, and chronic pelvic pain 2, 3
• Empiric treatment should be initiated when minimum criteria are met: uterine/adnexal tenderness OR cervical motion tenderness in sexually active women at risk for STDs 1
• Additional supportive findings include: oral temperature >101°F, abnormal cervical or vaginal mucopurulent discharge, presence of white blood cells on saline microscopy of vaginal secretions, elevated ESR or CRP 1
• If cervical discharge appears normal and no white blood cells are found on wet prep, PID is unlikely and alternative causes should be investigated 1
• Most commonly caused by Chlamydia trachomatis and Neisseria gonorrhoeae, but can involve bacterial vaginosis-associated pathogens and other organisms 2, 3

Cervicitis

• Inflammation of the cervix typically caused by Chlamydia trachomatis and Neisseria gonorrhoeae 3
• May present with vaginal discharge and lower abdominal discomfort 3
• Requires pelvic examination to differentiate from upper tract infection 3

Bacterial Vaginosis

• Common cause of vaginal discharge but typically does not cause significant abdominal pain 3
• Can be a co-pathogen in PID 2, 3
• Only requires treatment if symptomatic 3

Vulvovaginal Candidiasis

• Presents with thick white vaginal discharge resembling cottage cheese, itching, burning with urination, redness, and soreness 4
• Typically does not cause significant lower abdominal pain unless complicated 4, 3
• About three out of four adult women will have at least one vaginal yeast infection during their life 4

Ectopic Pregnancy

• Must be ruled out in all women of reproductive age before proceeding with further workup 5, 6
• Beta-hCG testing is mandatory in all women of reproductive age presenting with lower abdominal pain 5, 6
• Can present with vaginal discharge and lower abdominal pain 6

Adnexal Torsion

• Should be considered in women with acute onset lower abdominal pain 6
• Requires urgent imaging, typically with pelvic ultrasonography 6

Non-Gynecologic Gastrointestinal Causes

Appendicitis

• Most common cause of right lower quadrant pain requiring surgical intervention 1
• CT abdomen and pelvis with contrast has 95% sensitivity and 94% specificity for diagnosing appendicitis 1
• May present with atypical symptoms including vaginal discharge in some cases 7, 6

Diverticulitis

• Most common cause of left lower quadrant pain in adults 1
• CT is the initial imaging test of choice with sensitivity greater than 95% 1
• Typically occurs in older patients and may not be associated with vaginal discharge 1

Bowel Obstruction

• Accounts for approximately 15% of hospital admissions for acute abdominal pain 1
• Presents with intermittent abdominal pain, vomiting, and bowel closed to gas 1
• History of previous abdominal surgery has 85% sensitivity and 78% specificity for predicting adhesive small bowel obstruction 1

Gastroenteritis

• One of the most common causes of acute abdominal pain 6
• May present with diffuse abdominal pain and diarrhea 6
• Typically self-limited 6

Diagnostic Approach Algorithm

Step 1: Immediate Assessment

• Obtain beta-hCG in all women of reproductive age to rule out pregnancy-related conditions 5, 6
• Perform pelvic examination looking specifically for cervical motion tenderness, uterine tenderness, or adnexal tenderness 1
• Assess for hemodynamic stability and signs of sepsis 1, 6

Step 2: Laboratory Evaluation

• Complete blood count to assess for leukocytosis 5
• Urinalysis to evaluate for urinary tract infection 5
• Wet mount of vaginal secretions to look for white blood cells, which are present in most women with PID 1
• Cervical testing for N. gonorrhoeae and C. trachomatis 1
• ESR and CRP if PID is suspected 1

Step 3: Imaging Based on Clinical Presentation

• If PID criteria are met (cervical motion/uterine/adnexal tenderness), initiate empiric antibiotics immediately without waiting for imaging 1
• If diagnosis is unclear and patient is not pregnant: CT abdomen and pelvis with IV contrast is the imaging modality of choice 1, 6
• If pregnant and imaging needed: ultrasonography first, then MRI if inconclusive 6
• For right upper quadrant component: ultrasonography is initial test 1
• For suspected diverticulitis in left lower quadrant: CT with contrast 1

Critical Pitfalls to Avoid

• Failing to obtain pregnancy testing before imaging can lead to delayed diagnosis of ectopic pregnancy, which is life-threatening 5, 6
• Delaying antibiotic treatment for PID while awaiting test results increases risk of long-term sequelae including infertility 1, 2
• Assuming normal-appearing cervical discharge rules out PID—must check for white blood cells on wet prep 1
• Over-reliance on laboratory tests alone, as early findings may not differentiate among causes 5
• In immunocompromised patients, consider opportunistic organisms like Ureaplasma urealyticum that may require specialized testing 8

Special Population Considerations

Immunocompromised Patients

• May present with atypical symptoms and require involvement of multiple specialties 8
• Consider opportunistic microbes that might not be detected on routine testing 8
• May require more extensive diagnostic workup including laparoscopy if initial testing is negative 8

Elderly Patients

• May present with atypical symptoms 7
• Higher risk for serious pathology including bowel obstruction and diverticulitis 1