What is the primary symptom of Crohn's disease?

The primary symptom of Crohn's disease is stomach cramps. Crohn's disease is an inflammatory bowel disease (IBD) that can affect any part of the gastrointestinal tract, leading to various symptoms, with abdominal pain being a prominent feature. The inflammation in the bowel can cause cramps due to the digestive tract's irritation, which often manifests as painful, cramping sensations in the abdomen.

In addition to abdominal cramps, Crohn's disease can lead to a variety of gastrointestinal symptoms, including diarrhea and changes in bowel habits. While fatigue can occur due to the chronic nature of the disease and potential nutritional deficiencies, it is not the defining symptom. Weight gain is typically not associated with Crohn's, as many patients experience loss of appetite and weight loss due to malabsorption or increased energy expenditure from inflammatory processes. Heartburn is more commonly related to gastroesophageal reflux disease (GERD) rather than Crohn's. Thus, stomach cramps are central to the experience of individuals with Crohn's disease, making it the correct answer.