List and briefly explain at least 20 differential diagnosis of abdominal distension of 5 month duration in a 10 years old male

1. Irritable bowel syndrome (IBS) - a chronic condition that affects the large intestine and causes symptoms such as bloating, gas, and abdominal pain.

2. Inflammatory bowel disease (IBD) - a group of disorders that cause inflammation of the intestines, including Crohn's disease and ulcerative colitis.

3. Intestinal obstruction - a blockage in the intestines that can cause abdominal distension, pain, and vomiting.

4. Appendicitis - inflammation of the appendix that can cause abdominal pain, fever, and distension.

5. Gastroenteritis - inflammation of the stomach and intestines often caused by a viral or bacterial infection, leading to symptoms such as diarrhea, vomiting, and bloating.

6. Constipation - difficulty passing stool, leading to abdominal distension and discomfort.

7. Gastric outlet obstruction - a blockage in the stomach that can cause bloating and vomiting.

8. Lactose intolerance - the inability to digest lactose, a sugar found in dairy products, which can lead to symptoms such as bloating and diarrhea.

9. Pancreatitis - inflammation of the pancreas that can cause abdominal pain and distension.

10. Celiac disease - an autoimmune disorder triggered by consumption of gluten, leading to damage in the small intestine and symptoms such as bloating and diarrhea.

11. Intussusception - a condition where one segment of the intestine slides into another, causing obstruction and symptoms like abdominal distension and pain.

12. Parasitic infections - such as giardiasis or tapeworm infection, which can cause bloating and gastrointestinal symptoms.

13. Hepatitis - inflammation of the liver, which can lead to abdominal distension, jaundice, and other symptoms.

14. Ovarian cysts - fluid-filled sacs that form on the ovaries, causing abdominal bloating and discomfort.

15. Mesenteric ischemia - reduced blood flow to the intestines, leading to abdominal pain, distension, and potentially severe complications.

16. Abdominal tumors - such as neuroblastoma or Wilms tumor, which can cause abdominal distension and other symptoms.

17. Volvulus - a twisting of the intestines that can lead to obstruction and abdominal distension.

18. Malabsorption syndromes - conditions such as celiac disease or pancreatic insufficiency that interfere with the absorption of nutrients, causing bloating and other symptoms.

19. Enlarged lymph nodes - due to infections or lymphoma, which can lead to abdominal distension.

20. Ovarian torsion - a condition where the ovary twists on itself, cutting off blood supply and causing severe abdominal pain and distension.