Low calcium and phosphate may give a clue toward osteomalacia from low vitamin D.
Specific vitamins like vitamin D or micronutrient like zinc levels can be checked. Fat soluble vitamins (A, D, E and K) are affected in fat malabsorption. Prolonged prothrombin time can be caused by vitamin K deficiency. Serological studies. Specific tests are carried out to determine the underlying cause.IgA Anti-transglutaminase antibodies or IgA Anti-endomysial antibodies for Coeliac disease (gluten sensitive enteropathy). Stool studies
Microscopy is particularly useful in diarrhoea, may show protozoa like Giardia, ova, cyst and other infective agents. Fecal fat study to diagnose steatorrhoea is rarely performed nowadays. Low fecal pancreatic elastase is indicative of pancreatic insufficiency. Chymotrypsin and pancreolauryl can be assessed as well

Radiological studies
Barium follow through is useful in delineating small intestinal anatomy. Barium enema may be undertaken to see colonic or ileal lesions. CT abdomen is useful in ruling out structural abnormality,  done in pancreatic protocol when visualising pancreas. Magnetic resonance cholangiopancreatography (MRCP) to complement or as an alternative to ERCP. Interventional studies
OGD to detect duodenal pathology and obtain D2 biopsy (for coeliac disease, tropical sprue, Whipples disease, abetalipoproteinaemia etc.) Enteroscopy for enteropathy and jejunal aspirate and culture for bacterial overgrowth
Capsule Endoscopy is able to visualise the whole small intestine and is occasionally useful. Colonoscopy is necessary in colonic and ileal disease. ERCP will show pancreatic and biliary structural abnormalities. Other investigations
75SeHCAT test to diagnose bile acid malabsorption in ileal disease or primary bile acid diarrhea.
Heat syncope is fainting or dizziness as a result of overheating (syncope is the medical term for fainting). It is a type of heat illness. The basic symptom of heat syncope is fainting, with or without mental confusion. Heat syncope is caused by peripheral vessel dilation, resulting in diminished blood flow to the brain and dehydration. Signs and symptoms
Faintness, dizziness, headache, increased pulse, restlessness, nausea, vomiting, pale/clammy skin, and brief loss of consciousness. Causes
Heat syncope occurs in a warm environment when blood pressure is lowered as the body dilates (widens) arterioles (small blood vessels) in the skin to radiate heat. This condition occurs within five days of heat acclimatization, before the blood volume expands. The result is less blood to the brain, causing light-headedness and fainting when a person stands up quickly or stands for a long period of time. Those who perform strenuous work outside in warm climates are at particular risk. Diagnosis
The diagnosis of heat syncope is done during a physical examination. During the physical exam the practitioner will test the blood pressure of the patient, and the pulse. If the patient is experiencing heat syncope the blood pressure will be low, and the pulse will be elevated. Observation of excess sweating will also be a key sign. Finally, the practitioner will ask questions figuring out the history of the patients symptoms. If the patient developed symptoms while engaging in physical activity and high temperatures it will then be a true case of heat syncope.