When applying for Social Security disability due to gastrointestinal problems specific criteria must be met in order to receive benefits. Weight loss must be shown related to many conditions including stricture(narrowing) of the esophagus, bowel obstruction requiring surgery, inflammatory diseases of the bowel such as Crohn’s disease or ulcerative colitis and pancreatic disease. All of these may be associated with malabsorption; that is inability to absorbed necesssary nutrients from food resulting in a signficicant loss of weight.
Social Security has what is called a listing of diseases involving stomach and bowel problems. The key paragraph states weight loss due to any digestive disorder despite continuing treatment as prescribed with a BMI of less than 17.50 calculated on at least two evaluations at least 60 days apart and within a consecutive 6 month period. If one can meet these conditions(meeting the listing), then an allowance for benefits will be granted.
There is also another situation where benefits can be granted for a slightly less loss of weight associated with anemia, abdominal pain not completely controlled by narcotic medications or need for receiving additional nutrition by feeding tube or intravenously.
How to calculate BMI: Multiply your weight times 703, then multiply your height by itself. Last step; divide the first figure by the second.