Wainwright's Grain free = lots of poo

Hi,
when we were in Poland Debo was on German dry food, Bosch, it's not very good but good enough. Now we change his food for Wainwright's , first he had the normal one, duck flavour. And then I checked the grain free ones, it has lots of great reviews, so bought him rabbit one.
And he can poo 5x a day, all very solid, as it should be. But why so many? Is it because he's not use to so rich food?
"Composition and Nutrition^Main Flavour:Rabbit.

Ingredient(s):

Rabbit (37%) (Rabbit Meat Meal, Rabbit Gravy), Sweet Potato (30%), Potato (14%), Pea Starch(4%), Linseed (3%), Alfalfa (2%), Beet Pulp (2%), Rapeseed Oil (2%), Yeasts, Carrot (1%), Minerals, Tomato Powder (0.5%), Seaweed Meal (0.5%), Herbs (Marjoram 167 mg/kg, Oregano 167mg/kg, Sage 167 mg/kg, Parsley 167 mg/kg, Rosemary 167 mg/kg), Yucca (200 mg/kg), Cranberry (100 mg/kg), Marigold (50 mg/kg).

Additives:

Protein 27%; Crude Fibres 3%; Crude Oils and Fats 10%; Crude Ash 9%; Moisture 8%."

And I've put the post in the wrong place, sorry.

Could be he is allergic to one of the ingrediants and his body can't process the food properly so his wate has increased.

5 poo's in a day is quite a lot, sounds like the food is not being processed correctly in his digestive system.

Rabbit is very rich, it's the only meat Daisy won't touch!

ive just changed my puppys diet to wainwrights, and she loves it, was on eukanuba before but she didnt really seem to like it, i now give her 2 handulls of dry wainwrights with a spoonfull of wainwrights wet food, both grain free, i'm going to check this poo thing out as well, she is on the turkey flavour, i was going to get orijen but it costs a lot and hard to find in shops, can only get it online, if she has problems with this food then i will defo get orijen.