31st January 2024

Physical health differentials

Organic disorders leading to weight loss tend to be less common than the disorders above, and it is important not to fall into the trap of ordering a series of investigations for organic disorders whilst there is a person rapidly losing weight. The key point to determine the difference between an eating disorder and their differentials is the history of food avoidance. The only exception might be those who struggle to communicate and may be refusing food due to pain on swallowing or indigestion. Key organic differentials would include:

• Malabsorption disorders: Coeliac disease or inflammatory bowel disease. If comorbid coeliac is suspected, then it may be falsely negative in someone with low gluten intake. A CRP can be useful to add to blood tests to investigate inflammatory bowel disease. 
• Malignancy. Especially those causing brain-occupying lesions that might also induce vomiting 
• Chronic infections, e.g. HIV, tuberculosis
• Endocrine disorders, which may also cause a secondary amenorrhea
• Diabetes, though there is a high comorbidity between type 1 diabetes and anorexia