What causes a young girl to have a large lower abdomen?

1. Digestive issues: Abdominal pain may be caused by improper diet, food allergies, or food poisoning. 2. Constipation: Difficulty in bowel movements or irregular bowel habits can lead to abdominal pain. 3. Gastrointestinal inflammation: Inflammatory bowel diseases (such as Crohn's disease) or ulcerative colitis may cause abdominal pain. 4. Urinary tract infection: Urinary tract infections commonly present with symptoms such as abdominal pain, frequent urination, urgency, and painful urination. 5. Abdominal muscle strain: Excessive exercise or muscle injury may result in abdominal muscle pain. 6. Parasitic infection: If a girl has an intestinal parasitic infection, abdominal pain may occur, often accompanied by signs such as roundworms in stool, anal itching, or other related symptoms.