Table 2 Components of the Mayo score

Stool frequency

0 = Normal no. of stools for this patient

1 = 1 to 2 stools per day more than normal

2 = 3 to 4 stools per day more than normal

3 =  ≥ 5 stools per day more than normal

Rectal bleeding

0 = No blood seen

1 = Streaks of blood with stool less than half the time

2 = Obvious blood with stool most of the time

3 = Blood alone passes

Mucosal appearance at endoscopy^a

0 = Normal or inactive disease

1 = Mild disease (erythema, decreased vascular pattern, mild friability)

2 = Moderate disease (marked erythema, absent vascular pattern, friability, erosions)

3 = Severe disease (spontaneous bleeding, ulceration)

Physician rating of disease activity

0 = Normal

1 = Mild disease

2 = Moderate disease

3 = Severe disease