Self-reported dietary fructose intolerance in irritable bowel syndrome: Proposed diagnostic criteria

Table 1 Fructose-reduced diet (according to definition < 2 g fructose/meal)

Food item	In moderation	Use sparingly	Avoid
Fruit/berries	Lemon, raspberries, blueberries		All other types of fruit and berries
Vegetables	Most vegetables, avocado	Tomato purée	Carrots, legumes, boiled potatoes
Meat/fish/eggs	100% ground beef and fish with no additives	Caviar, mackerel in tomato sauce
		Anchovies and herring
Milk products	White/brown cheeses/cream and sour cream	Cheeses with fruit added	Fruit yoghurt, ice cream and puddings
Grain products	Bread, pasta, rice and white flour		Sweet bakery and cereals
Miscellaneous	Margarine, oils, mayonnaise, nuts	Dressings, ketchup	Sweets, chocolates
Drinks	Water, milk, tea, coffee, light soda and light fructose drinks	Light orange juice	Juice, nectar, sodas and fructose drinks, milk with sugar or fructose added

Table 2 Demographic and baseline variables for patients included

	All (77)	SRFI neg. (34)	SRFI pos. (43)	P value
Age, yr (median range)	43 (18-73)	46 (19-73)	43 (18-73)	NS1
Female/male ratio (%)	61/16	25/9	36/7	NS2
Abdominal pain/discomfort (mm)	53(3-89)	58 (3 89)	50 (16-76)	NS1
Bloating (mm)	55 (20-84)	58 (22-83)	54 (20-84)	NS1
Stool frequency [median (range)]	1.5 (0-4)	1.6 (1-4)	1.5 (0-4)	NS3
Boston scale stool consistency	4.4 (1.9-6.0)	4.6 (1.9-6.0)	4.3 (2.6-5.9)	NS1

¹Independent samples t-test;

²The χ² test;

³Mann-Whitney U. IBS: Measures are mean preregistration values (95%CI) unless otherwise stated. Treatment group differences were tested. SRFI: Self reported fructose intolerance; NS: Not significant.

Table 3 Pairwise comparisons of visual analog scale readings by ANOVA

SGA week 4	Model: F = 30.5; P < 0.0005	VAS difference, mean ± SE	P value	SGA week 4	Model: F = 32.6; P < 0.0005	VAS difference, mean ± SE	P value
VAS bloating	Adj R2 = 0.47			VAS pain/discomfort	Adj R2 = 0.46
Unchanged vs	Completely relieved	46.1 ± 6.1	< 0.0005	Unchanged vs	Completely relieved	41.1 ± 5.5	< 0.0005
	Considerably relieved	23.5 ± 3.0	< 0.0005		Considerably relieved	20.8 ± 2.7	< 0.0005
	Somewhat relieved	7.6 ± 2.8	0.066		Somewhat relieved	5.9 ± 2.5	0.202
	Worse	-7.4 ± 3.3	0.275		Worse	-9.4 ± 3.0	0.024

Results for two-way ANOVA: VAS by SGA × Diet. Mean differences in VAS change of SGA categories compared to unchanged, adjusted for diet type. P values were adjusted by Bonferroni correction. SGA: Subjective global assessment; VAS: Visual analog scale.

Table 4 Testing new diagnostic criteria of self-reported fructose intolerance in irritable bowel syndrome (for definition, see text) against fructose breath test and response of subjective global assessment test

Predictive	Sensitivity	Specificity	Positive predictive value	Negative predictive value	Kappa
FBT	0.57	0.34	0.58	0.29	-0.13
SGA weeks 3-41	0.79	0.75	0.82	0.71	0.53
SGA week 3-42	0.84	0.76	0.83	0.79	0.61

¹Without result provocation;

²With result provocation. SGA: Subjective global assessment; FBT: Fructose breath test.