Disorder	Populations affected/presumed etiology/food sources	Symptoms	Diagnosis/treatment
Carcinoid syndrome	Carcinoid tumors occur throughout adulthood and can develop in late childhood	Watery diarrhea with upper body flushing; symptoms may be provoked by eating (especially cheese) or alcohol intake	Measurement of 5-hydroxyindoleacetic acid from a 24-hour urine sample
Celiac disease	More common in white persons	Varied symptoms including diarrhea, malabsorption, weight loss, specific nutrient deficiencies	Immunoglobulin A antigliadin, antiendomysial, and antitissue transglutaminase antibodies are usually present Flattened duodenal villae on biopsy if patient has recently eaten gluten
	Symptoms can start at any age
	Sometimes associated with dermatitis herpetiformis
	Symptoms develop after gluten ingestion (wheat, barley, rye, and, more rarely, oats)
Giardiasis	Persons who have ingested water or food contaminated with Giardia cysts	Chronic symptoms of increased flatus, bloating, and diarrhea are often intermittent and recurring	Detection of Giardia antigen in stool Stool usually negative for occult blood or white blood cells
Giardiasis	Fecal-oral spread also occurs in child daycare settings
Gustatory rhinitis	Believed to be nonallergic and mediated through vagus nerve	Nasal congestion and rhinorrhea after eating hot or spicy foods	No specific tests Diagnosed by characteristic history
Irritable bowel disease	Chronic symptoms usually start in young adulthood (before 40 years of age)	No weight loss or fevers Cramping abdominal pain, often with increased flatus Symptoms often increase with eating Diarrhea can alternate with constipation, or one may be predominant	Stool will be negative for occult blood or white blood cells Complete blood count will be normal
Lactase deficiency*	Primary deficiency much more likely to develop in adulthood in nonwhite persons, but lesser degrees of lactase deficiency can be found in 25 percent of white persons	Diarrhea, abdominal pain, and increased flatus after ingestion of dairy products	pH in stool will be decreased Trial elimination of dairy products Breath test for hydrogen
Scombroid poisoning	Bacterial production of excess amines, particularly histamine on food	Patients quickly develop paresthesias, burning sensations, headaches, and pruritus after food ingestion	Portion of the suspected food is tested for histamines Patients improve with antihistamines
Scombroid poisoning	Most cases from tuna, mahi-mahi, and swiss cheese
Sulfite ingestion†	Sulfites have been banned by the U.S. Food and Drug Administration for preserving raw fruits and vegetables, but they are still found in a variety of cooked and processed foods	Allergic reactions Inhalation produces bronchospasm in about 5 percent of patients with asthma	Treat with beta-agonist inhalers and future avoidance in affected persons with asthma Patients who have sensitivity secondary to sulfite oxydase deficiency can be treated with vitamin B₁₂