A 28-year-old woman presents with long-standing constipation, which she reports has been getting worse over time. She also experiences periodic abdominal pain that she describes as 'cramping.' She denies any history of blood in the stool, weight loss, or any systemic symptoms. What is your primary diagnosis?
The symptoms of long-standing constipation and periodic abdominal cramping suggest a diagnosis of Irritable Bowel Syndrome with Constipation (IBS-C). Her age, absence of systemic symptoms, and lack of red flag symptoms like blood in the stool or weight loss support the diagnosis of IBS. However, additional workup including blood tests and potentially imaging or endoscopy may be necessary to rule out other disorders that can cause similar symptoms.