Gastroparesis: This condition, characterized by delayed stomach emptying, can lead to persistent intolerance to solid food and vomiting shortly after eating. The absence of associated symptoms like abdominal pain or changes in bowel habits and unremarkable liver function tests, lipase, and amylase levels does not rule out gastroparesis, as it primarily affects gastric motility.

Functional Dyspepsia: A common condition that can cause persistent or recurrent upper abdominal symptoms, including nausea, vomiting, and intolerance to food, without evidence of organic disease. The lack of associated symptoms and normal laboratory tests supports this diagnosis.
Eating Disorders (e.g., Bulimia Nervosa): Although psychological factors are primary, the physical act of self-induced vomiting can lead to food intolerance due to esophageal dysfunction or fear of eating.
Gastroesophageal Reflux Disease (GERD): Can cause vomiting and intolerance to solid foods, especially if symptoms are severe and not adequately managed.

Mechanical Obstruction (e.g., Pyloric Stenosis, Gastric Outlet Obstruction): Although less likely given the chronic nature and lack of other symptoms, any form of mechanical obstruction can lead to vomiting after eating and must be considered to avoid missing a potentially life-threatening condition.
Neoplastic Disease (e.g., Gastric Cancer): Though rare, especially in younger populations, gastric cancer can present with nonspecific symptoms like food intolerance and vomiting. It's crucial to rule out such conditions, especially with persistent symptoms.
Inflammatory Conditions (e.g., Eosinophilic Gastroenteritis): Can cause gastric dysfunction leading to food intolerance and vomiting. These conditions might not always present with typical inflammatory markers or symptoms.

Rumination Syndrome: A condition where food is regurgitated and then chewed and swallowed again, which can lead to food intolerance and vomiting.
Cyclic Vomiting Syndrome: Characterized by recurrent episodes of severe vomiting lasting hours to days, with periods of normal health in between. It might present with food intolerance during episodes.
Mitochondrial Neurogastrointestinal Encephalomyopathy (MNGIE): A rare genetic disorder affecting the gastrointestinal system, among other things, leading to severe gastrointestinal dysmotility, which can cause food intolerance and vomiting.