Should you start SCD while flaring? Well it can't hurt because it's a healthy diet, but it does require extra effort to find/cook different food than usual and that could
add to your stress level. Can it help? Maybe. I can only speak from my own experience and that is, the first time I tried SCD I was really flaring badly, to the extent that the only food that my colon could tolerate were eggs and chicken. I was not successful with SCD at that time and it made me think it didn't work. Years later I tried SCD again and it gave me my life back.
The danger, as I see it, by trying SCD in a flare, is that it won't take and you will think it won't work and chalk it up to another "cure" that doesn't work for you.
As I mentioned on another thread I wish I had started SCD when I was at my best, during a short steroid (Entocort) course a couple years ago. That would have given my colon a jump-start on repair. But hindsight is 20-20. The way I started SCD in Jan 2010 I was able to tell that SCD was working because nothing else changed except starting the diet and I started getting better.
SCD works slowly, perhaps too slowly for people who want faster results. It's interesting that docs say (and people listen) that certain drugs may take months to get results. SCD is the same way but because it doesn't have medical support is abandoned prematurely. In my case I didn't have any other options I wanted to pursue (Remicade and surgery were not what I wanted) so when I tried SCD this time I had nothing to lose.
In remission April 2010 after 10 years of suffering and no remission ever
Jan 2010 started SCD diet (modified to remove dairy, fruit & juices)
Gluten-free=bleeding stopped in 3 days, 95% remission in 5.5 months on SCD
at 5.5 month stage homemade yogurt, hard cheese and some fruit OK
SCD Diet: Gluten/grain-free, starch-free, low carb, low-sugar
Supplements: tsp. fish oil, Vit D3 5000 with oil/fat, veggie juice, sunflower seeds, VSL#3, (4) Citrucel, (1) turmeric capsule, (1) calcium
Highly recommend: the book "Life without Bread" and the Specific Carbohydrate Diet
Rx: (6) balsalazide daily, mesalamine enema occasionally