Differential Diagnosis for Young Women with Idiopathic Nausea and Constipation

Single Most Likely Diagnosis

• Irritable Bowel Syndrome (IBS): This is a common condition characterized by chronic abdominal pain, bloating, and alteration of bowel habits in the absence of any mechanical, inflammatory, or biochemical abnormalities. Nausea and constipation are common symptoms, especially in young women.

Other Likely Diagnoses

• Gastroesophageal Reflux Disease (GERD): While more commonly associated with heartburn, GERD can also cause nausea. Constipation might not be a direct symptom but can occur due to decreased gut motility or as a side effect of certain medications.
• Hypothyroidism: This condition can cause gastrointestinal symptoms including nausea and constipation, among others like fatigue and weight gain. It's more common in women and can be idiopathic or autoimmune in nature.
• Anxiety or Depression: These conditions can manifest with gastrointestinal symptoms, including nausea and changes in bowel habits. The psychological aspect can sometimes make these conditions overlooked in favor of more "physical" diagnoses.

Do Not Miss Diagnoses

• Pregnancy: Although it might seem obvious, pregnancy should always be considered in women of childbearing age presenting with nausea, as it is a critical diagnosis that needs to be identified early.
• Inflammatory Bowel Disease (IBD): Conditions like Crohn's disease and ulcerative colitis can present with nausea and constipation, among other symptoms. Missing these diagnoses can lead to significant morbidity.
• Obstruction or Intussusception: Although less common, these conditions can cause severe nausea and constipation. They are medical emergencies requiring prompt intervention.

Rare Diagnoses

• Gastroparesis: A condition where the stomach takes too long to empty its contents. It can cause nausea, vomiting, and constipation due to slowed gut motility.
• Celiac Disease: An autoimmune disorder where the ingestion of gluten leads to damage in the small intestine. It can cause a variety of gastrointestinal symptoms, including nausea and constipation.
• Neurological Disorders (e.g., Parkinson's Disease, Multiple Sclerosis): Certain neurological conditions can affect gut motility and cause symptoms like nausea and constipation. These are less common but should be considered in the appropriate clinical context.