Jejunal diseases refer to a group of medical conditions that affect the jejunum, which is the second part of the small intestine. The jejunum plays a crucial role in nutrient absorption and digestion. Jejunal diseases can cause various symptoms such as abdominal pain, diarrhea, weight loss, and malnutrition. Some examples of jejunal diseases include:

1. Celiac disease: an autoimmune disorder that causes damage to the small intestine lining when gluten is consumed.
2. Crohn's disease: a type of inflammatory bowel disease that can affect any part of the gastrointestinal tract, including the jejunum.
3. Jejunal diverticulosis: the presence of small pouches or sacs that form on the jejunum's wall, which can become inflamed or infected.
4. Intestinal lymphangiectasia: a rare condition characterized by dilated lymphatic vessels in the jejunum, leading to protein loss and malnutrition.
5. Jejunal atresia: a congenital condition where there is a blockage or absence of a portion of the jejunum.
6. Bacterial overgrowth: an excessive growth of bacteria in the small intestine that can cause diarrhea, bloating, and malabsorption.
7. Radiation enteritis: damage to the jejunum caused by radiation therapy used to treat cancer.

The specific treatment for jejunal diseases varies depending on the underlying condition but may include medications, dietary changes, or surgery.