I have colitis, with an acidic PH for both saliva and urine. After reading Ted's comments, I have tried magnesium citrate, as well as lime and baking soda for months. But what did the trick for me to reduce the pain of colitis was: I used 1/2 teaspoon baking soda twice a day: once in the morning and once 30 minutes to 1 hour before bedtime. I put the baking soda into emptied geletin capsules ( about 3 capsules) and down them with a 1/2 glass of water ( the taste is too salty for me without the capsule. also, I didn't want the stomach acid to neutralize it before it gets down further in the intestine. If you don't use the capsules, use more water to make it more dilute so it doesn't burn or irritate the intestinal lining.) Then about 10 minutes before bedtime, I take one or two capsules of activated charcoals with 1/2 glass of water ( the brand I buy has 280 mg of activated charcoal in each capsule, thus 560 mg total if taking two. you can find this on the internet. If not, I am thinking activated carbons sold by fish pet shops might work similarly ( I personally have not tried this yet, but I would if I couldn't find any activated charcoals. If you have to use the carbon, please write in your feedback to others), but you will have to pulverize it or ground it up to make it into a fine powder to increase its absortive surface).
Reviews I read on activated charcoal uses include all kinds of stomach ailments including against food poisoning. I remember I had bought some potting soil once that had small pieces of charcoals in them to absorb the bad smell of bacteria. To experiment, I bought activated carbons from Walmart at the pet fish section and sprinkled a little to put into peatmoss for my potting soil. Results: the plants grew small and skinny dispite all the fertilizers I put in compare to similar other pots without the activated carbon. Lesson: The activated carbon absorbed so well it absorbed the fertilizer as well. The label warns that high absorbancy of activated charcoal may reduce the effectiveness of certain medications, thus take it at least 2 hours AWAY from your regular medications or vitamin/mineral supplements. I take mine right before bedtime so that it can have hours without interference from any food to work it's way through the intestines and absorb all the foul bacterias in there. If your colitis is highly active right now, you might consider increase the frequency of activated charcoal, perhaps up to three times per day. I saw results in mine less than a week. There is also the option of adding the activated charcoal to a water based enema, although I hadn't needed to use it this way. Use filtered water for this as regular water has clorine. Once the colitis is under control, I would reduce the amount and frequency used, again, because it will absorb your food and nutrients as well as the bad bacteria. You might consider taking some probiotics as well afterwards to build back the good gut flora.
If you have an acidic ph and it deems that you take baking soda, I strongly recommend you take a good quality vitamin B-complex, vitamin D, along with extra sublingual(under the tongue) folic acid and B-12 to ward against some of the side effects I read under the Baking Soda section on Earthclinic website. I recommend sublingual because I have read that some people's gut don't have the neccesary bacteria to breakdown and absorb the b-12, and that people with autoimmune diseases usually have deficient folic acid and vitamin d in their blood.
I have also found that both L-Glutamine and Sweet Dairy Whey have a firming quality in that they dry and firm up loose stools. So if you need to take magnesium citrate to alkalize the body( magnesium has a laxative effect), you might add 1 to 2 tablespoon l-glutamine or sweet whey to reduce the side effects of magnesium. While those who suffers from constipation in their colitis may want to add magnesium citrate to see if there is any relief.
All in all, ulcerative colitis is a bugger of a disease to battle! One med may work today but not another day. I hope my personal experience can offer those in active stages one more option to try to get this disease under control. Thanks, Ted! and Thanks Earth Clinic!