How should I evaluate and manage a 35-year-old woman with severe epigastric tenderness that began on the first day of her menstrual period, brown-colored sputum on waking, and a normal upper gastrointestinal endoscopy performed one year ago?

Severe Epigastric Tenderness on First Day of Menstruation with Brown Sputum

This patient requires urgent evaluation for bowel endometriosis and immediate exclusion of cardiac causes, followed by upper endoscopy if alarm features persist, as cyclic epigastric pain synchronized with menstruation in a woman with prior endometriosis history is pathognomonic for intestinal endometriosis until proven otherwise. 1

Immediate Assessment (Within Hours)

Rule Out Life-Threatening Causes First

• Obtain ECG and cardiac troponins immediately to exclude myocardial infarction, as acute coronary syndrome can present with epigastric pain as the primary manifestation and carries 10-20% mortality if missed 2
• Check vital signs for tachycardia (≥110 bpm), fever (≥38°C), or hypotension, which predict serious complications like perforation or sepsis 2, 3
• Perform abdominal examination specifically assessing for peritoneal signs (board-like rigidity, rebound tenderness, absent bowel sounds), as these indicate perforated peptic ulcer with 30% mortality if treatment is delayed 4, 2

Critical Red Flag: Menstrual Synchronization

The timing of severe epigastric pain occurring specifically on day 1 of menstruation is highly suspicious for bowel endometriosis, particularly given the brown sputum suggesting possible diaphragmatic/thoracic endometriosis. 1 A case report documented a 35-year-old woman with epigastric pain exclusively during menstruation who had bowel endometriosis at the ileocecal junction despite normal upper endoscopy 1. This is not functional dyspepsia or typical peptic ulcer disease.

Diagnostic Workup Algorithm

Step 1: Laboratory Evaluation

• Complete blood count (assess for anemia from occult bleeding) 2
• Comprehensive metabolic panel 2
• C-reactive protein (elevated in inflammatory conditions) 2
• Serum amylase/lipase (exclude pancreatitis) 2

Step 2: Imaging for Endometriosis

Order transvaginal ultrasound and pelvic MRI immediately to evaluate for bowel endometriosis, as these modalities can identify lesions involving the intestinal tract 1. The brown sputum on waking suggests possible thoracic endometriosis (catamenial hemoptysis), which would further support this diagnosis.

Step 3: Upper Endoscopy Considerations

While her endoscopy one year ago was normal, repeat endoscopy is NOT the priority here unless alarm features develop 4. The British Society of Gastroenterology states that endoscopy should be performed for:

• Age ≥55 years with treatment-resistant dyspepsia 5, 4
• Weight loss with dyspepsia 5, 4
• Persistent vomiting 5, 3

She does not meet these criteria, and her menstrual synchronization points away from peptic pathology.

Step 4: CT Abdomen/Pelvis with IV Contrast

If pelvic imaging is inconclusive but clinical suspicion remains high, obtain CT abdomen/pelvis with IV contrast to evaluate the entire gastrointestinal tract for endometriotic implants 5, 3. CT can identify bowel wall thickening, fat stranding, and masses that may represent endometriosis 5.

Immediate Management

Symptomatic Relief

• Start high-dose PPI therapy: omeprazole 40 mg once daily while awaiting definitive diagnosis, as this provides symptomatic relief if any peptic component exists 2, 3
• Consider ondansetron 8 mg sublingual every 4-6 hours for nausea if present (obtain baseline ECG first due to QTc prolongation risk) 3

Hormonal Suppression Trial

If imaging confirms or strongly suggests endometriosis, initiate continuous oral contraceptives to suppress menstruation and prevent cyclic symptom recurrence 1. This approach has demonstrated symptom control in patients with menstruation-triggered symptoms.

Common Pitfalls to Avoid

1. Do not assume this is functional dyspepsia or GERD simply because prior endoscopy was normal. The Rome IV criteria require symptoms for 3 months with onset 6 months prior 5, and the menstrual synchronization is atypical for functional disease 1.

2. Do not dismiss the brown sputum as unrelated. This may represent catamenial hemoptysis from thoracic endometriosis, which would indicate multifocal disease requiring comprehensive evaluation.

3. Do not delay gynecologic consultation. If bowel endometriosis is confirmed, she will require laparoscopic resection by a surgeon experienced in endometriosis, as medical management alone is often insufficient 1.

4. Do not repeat upper endoscopy as the first test. Her normal study one year ago and the menstrual timing make upper GI pathology unlikely as the primary cause 1.

Referral Pathway

Urgent gynecology referral (within 1-2 weeks) for evaluation of suspected bowel endometriosis, particularly if:

• Pelvic imaging demonstrates endometriotic lesions 1
• Symptoms recur with subsequent menstrual cycles 1
• Conservative management fails to control symptoms 1

Gastroenterology referral is appropriate only if:

• Alarm features develop (weight loss, dysphagia, persistent vomiting) 5, 4
• Symptoms persist beyond 8 weeks despite optimized PPI therapy AND imaging excludes endometriosis 2
• Age ≥55 years with treatment-resistant symptoms 5, 4