What is the likely diagnosis for a 43-year-old woman with irregular bowel habits and crampy abdominal pain but no weight loss or blood in her stools?

The diagnosis of irritable bowel syndrome (IBS) is particularly fitting for a 43-year-old woman who presents with irregular bowel habits and crampy abdominal pain without accompanying weight loss or blood in her stools. IBS is a functional gastrointestinal disorder characterized by a combination of symptoms, including abdominal discomfort or pain associated with changes in bowel habits, which may include diarrhea, constipation, or alternating patterns.

The absence of alarming symptoms such as weight loss or blood in the stool further supports the IBS diagnosis, as these features would typically suggest more serious underlying conditions that may require additional investigation or intervention. The crampy nature of the abdominal pain is also characteristic of IBS, often caused by increased bowel motility or muscle contractions.

Other conditions mentioned, like acute diverticulitis and Crohn's disease, usually present with more severe symptoms, including significant abdominal pain, fever, and possible gastrointestinal bleeding, which are not present in this case. Abdominal migraines may cause episodic abdominal pain, but they do not typically manifest as irregular bowel habits, making IBS the most likely diagnosis in this scenario.