Fig. 1:

The severity and frequency of GI disorder symptoms assessed by Likert scale

Severity: 0, absent, 1, mild (without influence on daily activities); 2, relevant (interfering with daily activities but not urging modification); 3, have influence in daily activities with urge modification)

Frequency: 1, occurring < 1 d/mo; 2, occurring 1 d/mo; 3, occurring 2–3 d/mo; 4, occurring 1 d/wk; 5, occurring > 1 d/wk; 6, occurring every day