Differential Diagnosis for Bilious Vomiting

Single Most Likely Diagnosis

• Intestinal Obstruction: This is often the most common cause of bilious vomiting, especially in adults. The obstruction can be due to various reasons such as adhesions, hernias, or tumors, leading to the accumulation of bile in the stomach, which is then vomited.

Other Likely Diagnoses

• Gastroenteritis: Infections of the gastrointestinal tract can cause inflammation and lead to bilious vomiting, especially if the infection involves the small intestine where bile is present.
• Appendicitis: Although more commonly associated with abdominal pain, appendicitis can sometimes present with vomiting, which may be bilious if the appendix is located near the junction of the small and large intestines.
• Cholecystitis: Inflammation of the gallbladder can cause bilious vomiting due to the obstruction of bile flow.

Do Not Miss Diagnoses

• Volvolus: A condition where the intestine twists around itself or its mesentery, cutting off its blood supply. It's a surgical emergency and can present with bilious vomiting.
• Intussusception: A condition where a part of the intestine slides into an adjacent part, potentially cutting off blood supply. It's more common in children but can occur in adults and is a surgical emergency.
• Mesenteric Ischemia: Reduced blood flow to the intestines can cause severe abdominal pain and bilious vomiting. It's a medical emergency requiring prompt intervention.

Rare Diagnoses

• Congenital Anomalies: In newborns, conditions like pyloric stenosis (though typically non-bilious), intestinal malrotation, or Hirschsprung's disease can cause bilious vomiting.
• Cystic Fibrosis: Can cause intestinal obstruction due to thickened secretions, leading to bilious vomiting.
• Chron's Disease: A type of inflammatory bowel disease that can cause narrowing of the intestine, leading to obstruction and bilious vomiting.

Each of these diagnoses has a different set of risk factors, symptoms, and diagnostic approaches, emphasizing the importance of a thorough medical history, physical examination, and appropriate diagnostic testing to determine the underlying cause of bilious vomiting.