Recently it has been reported that a consistent percentage of the general population consider themselves to be suffering from problems caused by wheat and/or gluten ingestion, even though they do not have CD or wheat allergy. This clinical condition has been named Non-Celiac Gluten Sensitivity' (NCGS). In a previous paper the investigators suggested the term 'Non-Celiac Wheat Sensitivity' (NCWS), since it is not known what component of wheat causes the symptoms in NCGS patients, and the investigators also showed that these patients had a high frequency of coexistent multiple food hypersensitivity. The clinical picture of NCWS is characterized by combined gastrointestinal (bloating, abdominal pain, diarrhea and/or constipation, nausea, epigastric pain, gastroesophageal reflux, aphthous stomatitis) and extra-intestinal and/or systemic manifestations (headache, depression, anxiety, 'foggy mind,' tiredness, dermatitis or skin rash, fibromyalgia-like joint/muscle pain, leg or arm numbness, and anemia). Nowadays no data are available on the abdominal ultrasonographic features of NCWS patients. Therefore, the aim of the present study is to evaluate the abdominal ultrasonographic features of NCWS patients in comparison with patients affected with celiac disease.

Recently it has been reported that a consistent percentage of the general population consider themselves to be suffering from problems caused by wheat and/or gluten ingestion, even though they do not have CD or wheat allergy. This clinical condition has been named Non-Celiac Gluten Sensitivity' (NCGS). In a previous paper the investigators suggested the term 'Non-Celiac Wheat Sensitivity' (NCWS), since it is not known what component of wheat causes the symptoms in NCGS patients, and the investigators also showed that these patients had a high frequency of coexistent multiple food hypersensitivity. The clinical picture of NCWS is characterized by combined gastrointestinal (bloating, abdominal pain, diarrhea and/or constipation, nausea, epigastric pain, gastroesophageal reflux, aphthous stomatitis) and extra-intestinal and/or systemic manifestations (headache, depression, anxiety, 'foggy mind,' tiredness, dermatitis or skin rash, fibromyalgia-like joint/muscle pain, leg or arm numbness, and anemia). The researchers have just demonstrated in patients affected with seronegative celiac disease that the presence of dilated bowel loops and a thickened small bowel wall had a sensitivity of 83% and a negative predictive value of 95% in CD diagnosis. Considering the presence of one of these two signs, abdominal US sensitivity increased to 92% and negative predictive value to 98%. Nowadays no data are available on the abdominal ultrasonographic features of NCWS patients. Therefore, the aim of the present study is to evaluate the abdominal ultrasonographic features of NCWS patients in comparison with patients affected with celiac disease.

Inclusion Criteria:

To diagnose NCWS the recently proposed criteria will be adopted. All the patients will meet the following criteria:

• negative serum anti-transglutaminase (anti-tTG) and anti-endomysium (EmA) immunoglobulin (Ig)A and IgG antibodies
• absence of intestinal villous atrophy
• negative IgE-mediated immune-allergy tests to wheat (skin prick tests and/or serum specific IgE detection)
• resolution of the IBS symptoms on standard elimination diet, excluding wheat, cow's milk, egg, tomato, chocolate, and other self-reported food(s) causing symptoms
• symptom reappearance on double-blind placebo-controlled (DBPC) wheat challenge. As the investigators previously described in other studies, DBPC cow's milk protein challenge and other "open" food challenges will be performed too.

To diagnose CD the standard criteria will be adopted. All the patients will meet the following criteria:

• positive serum anti-transglutaminase (anti-tTG) and anti-endomysium (EmA) immunoglobulin (Ig)A and IgG antibodies
• presence of intestinal villous atrophy.

Exclusion Criteria:

NCWS diagnosis excluded patients with:

• positive EmA in the culture medium of the duodenal biopsies, also in the case of normal villi/crypts ratio in the duodenal mucosa
• self-exclusion of wheat from the diet and refusal to reintroduce it before entering the study
• other previously diagnosed gastrointestinal disorders
• nervous system disease and/or major psychiatric disorder
• physical impairment limiting physical activity.

The study included consecutive adult patients with IBS-like clinical presentation, according to Rome III criteria, and a definitive diagnosis of NCWS, referred at the Department of Internal Medicine at the University Hospital of Palermo, Italy, and at the Department of Internal Medicine of the Hospital of Sciacca, Agrigento, Italy, between January 2015 and November 2016, and sex- and age-matched subjects with CD, enrolled at the same centers, as controls patients. All subjects undergone abdominal ultrasonography at the Outpatient of Ultrasonography of the Department of Internal Medicine at the University Hospital of Palermo, Italy.