TLDR context:

• I have completely controlled Crohn's disease for about 35 years using Azathioprine (Imuran) on what is a very low dose, for most people (100 mg / day).
• Three months ago I picked up a stomach bug from some dodgy food. Somehow, it reactivated the Crohn's, and azathioprine is no longer containing the disease.
• I tried increasing the dose to 150 mg, which worked, after about a month. But blood tests showed the metabolites were at toxic levels (six times acceptable limit). I had to go back to 100 mg, and got sick again. I've done two cycles of this.
• For me, Crohn's disease is progressive without remission. If I don't find a solution it will kill me.

Plan B: Keto diet accidentally goes carnivore

Since I can't tolerate a higher dose of azathioprine, I decided to try and increase the effective dose by losing weight. The idea is that if I can lose, say, 10 kg, that might be equivalent to taking a few milligrams more without actually increasing the absolute dose.

I know from experience that strict keto diets are very effective for weight loss, and easier to manage because they damp down hunger. So I have been strictly avoiding carbohydrates for the last three weeks or so, limiting the amount I eat to the bare minimum. Unintentionally, this somehow turned into a mostly carnivore diet. I'm no puritan, so a bit of sauce might fall onto my steak or whatever. I've lost two kilos so far (not including another kilo of fluid that you shed after the first few days).

Unintended consequences: Improvement

After the first couple of weeks my symptoms unexpectedly improved. I'm not quite normal but feel ok most of the time. I don't think I've lost enough weight yet to make an impact, so it's something about the food, which has largely been meat (whey protein, beef, chicken, fish, pork) including the fat, plus olive oil, cheese, small amounts of mixed nuts, and supplements including fish oil.

Why is it working?

I don't yet know, but plan to find out:

• Is it simply the low volume of low-residue food?
• Is there something about carbohydrates that is fueling Crohn's disease?
• Does ketosis itself somehow reduce Crohn's symptoms?
• Or do you need the full carnivore diet to benefit?

Bowel rest is a legitimate treatment for Crohn's, so it could just be a function of the low volume of low residue foods. If that's the case, the benefits are probably not sustainable and I would expect to get sick as soon as I increase food volume (calories) back to maintenance levels.

Pretty much everyone that gets Crohn's tries an elimination diet, so I'm sceptical that carbohydrates are the cause, but then few would have tried eliminating carbohydrates as a class. Normally people will rotate between different carbohydrate sources to test them.

As for ketosis, there is an increasing body of scientific evidence that it can be a useful treatment for a surprisingly wide range of diseases, including obviously diabetes, but also epilepsy, immune conditions and many more.

Carnivore diets are basically a more restrictive form of ketogenic diet, so it is not surprising that it also has benefits for a wide range of diseases. And there are a few videos out there by people claiming to have treated Crohn's with hardcore carnivore diets. I had discounted these as cranks, but now I think I should take a closer look.

Testing the hypothesis

After I hit my target weight (two months or so) I will run a few tests, gradually reducing controls to see if there are observable impacts:

1. Increase food volume (calories) to maintenance while maintaining a carnivore diet. The idea here is to see whether it was bowel rest that improved my symptoms.
2. Shift to a keto diet with diverse plant content. I'll be adding salad and non-starchy vegetables to maintain ketosis, but abandoning a carnivore diet.
3. Shift to low carb (non-keto) diet. I will add small amounts of carbohydrate, enough to break ketosis but I do not plan on eating huge amounts of carbs again.

My feeling is that the low carb diet will fail. But we'll see.

Just so you know

Just to be clear, I'm still taking the azathioprine and it is still providing some degree of suppression, I can't live without it. So this is actually a combined treatment. There is no way a diet alone is going to 'cure' me.

I am not a dietary zealot. I do not want to be on a carnivore or keto diet. I just want to eat pizza and live a normal life. But for people with Crohn's or other auto-immune diseases, sometimes there are no good choices. Sometimes the choice is the devil or the deep blue sea.