Differential Diagnosis for Lower Abdominal Pain, Vomiting, and Diarrhea in a 36-Week Pregnant Woman

• Single Most Likely Diagnosis
  • Gastroenteritis: This is a common condition characterized by inflammation of the gastrointestinal tract, often caused by viral or bacterial infections. The symptoms of lower abdominal pain, vomiting, and diarrhea, especially with a sudden onset, are consistent with gastroenteritis. Pregnancy can sometimes exacerbate the symptoms due to hormonal changes and pressure on the abdomen.
• Other Likely Diagnoses
  • Urinary Tract Infection (UTI): UTIs are common during pregnancy due to physiological changes that can predispose women to infection. Symptoms can include lower abdominal pain, nausea, vomiting, and sometimes diarrhea.
  • Preterm Labor: Although the primary symptom of preterm labor is uterine contractions leading to cervical change, it can sometimes be preceded by gastrointestinal symptoms like diarrhea and vomiting, possibly due to the release of prostaglandins.
  • Food Poisoning: Similar to gastroenteritis, food poisoning can cause sudden onset of vomiting, diarrhea, and abdominal pain. Pregnancy might increase susceptibility due to changes in the immune system.
• Do Not Miss Diagnoses
  • Appendicitis: Although less common, appendicitis can occur during pregnancy and may present with atypical symptoms due to the upward displacement of the appendix by the gravid uterus. It's crucial to consider appendicitis due to its potential for severe complications if not promptly treated.
  • Placental Abruption: This condition involves the premature separation of the placenta from the uterus and can cause abdominal pain, vomiting, and sometimes diarrhea. It's a medical emergency that requires immediate attention.
  • Preeclampsia: While primarily characterized by hypertension and proteinuria, severe preeclampsia can cause epigastric or right upper quadrant pain, nausea, vomiting, and sometimes diarrhea. It's a critical condition that can lead to significant maternal and fetal morbidity if not recognized and managed promptly.
• Rare Diagnoses
  • Intussusception: A rare condition where a part of the intestine slides into an adjacent part, potentially causing bowel obstruction. It can present with abdominal pain, vomiting, and sometimes diarrhea, but it's exceedingly rare in adults and even more so in pregnant women.
  • Mesenteric Ischemia: This involves insufficient blood flow to the intestines and can cause severe abdominal pain, vomiting, and diarrhea. It's rare but can be life-threatening and requires immediate medical intervention.