The Gut and Psycology Syndrome (GAPS) diet is a very basic way of eating and is meant to heal the gut. This is a no risk program and can cure anything from diarrhea to food allergies and autoimmune diseases. It is composed of 5 stages and can be implemented according to the severity of the symptoms. Although it is restrictive there are many great foods that can be eaten. If one is currently practicing a loose version of Paleo then this shouldn’t be much harder or different.
This is a downloadable PDF article that summarizes the different stages:: adapted_gaps_intro_diet
What can you eat on the GAPS diet? This is an excellent source and explanation: http://www.healthhomehappy.com/2012/11/what-can-you-eat-on-the-gaps-diet.html
For more detailed information you may as well go to the source: http://www.gapsdiet.com