As of right now, I can digest most foods fine with an exception of alcohol. I can overeat if I wanted to without getting heartburn. However, I do feel discomfort after overeating or consuming unhealthy meals.

My bowel movement isn't very regular, maybe once a day or once every two days. Stool has severe odor, and this has been happening for a decade...

Are you going to be serious about things or pretend that some supplements will make things ok. 10 years of problems = at least 2-3 years of solution, even when you find the right solution.

Digestive problems worsened after taking a lot of homemade fermented foods and Prescript Assist (soil based probiotics) in November of 2014. Since then, I've been suffering from dysphagia (lingering food sensation in throat).

Stop the fermented foods or learn how to deal with the cleansing. dysphagia or gallstones, you decide. THEY have a dys word for every new symptom under the sun.

Initially, I suggested candida overgrowth, then parasites. So I consumed diatomaceous earth (food grade) for a month. However, DE actually made more problems by worsening constipation. I know for sure that my body is not creating enough stomach acid because I can take Betaine HCL up to 6 pills with only minor discomfort. In addition, my tummy makes a lot of growling noise.

10 years of constipation, probably more. And you decided candida? You need to read more or find a proper doctor/shaman/herbalist/internet denizen/etc to help you if you cannot diagnose yourself properly - as many people cannot. And this story is getting more familiar by the second.  Parasites, yeast, fungus, protozoa, bacteria, sludge, stones, all of the above and more. Keep on the hcl supplements. The marginally intelligent 'Dr' Jeff is good at helping people with finding the dosage according the the Einsteinian brilliance of up the dose until you feel a burn. Pure genius.

Stop eating wheat

My physician and I have no idea what is going on anymore and I plan to try other parasite supplements.

Well it certainly is difficult to find what's going on since there are about 10 billion websites, and 2 million books on the subject that could at least help you feel better within a few days.

My question is, can parasite reside for a long period of time if no treatment is given?

Yes and they can multiply

Also, I thought DE was one of the best supplements you can take for killing parasites by dehydrating the eggs and living culture.

It is.

Are other supplements actually more effective at killing specific parasites?

Probably.

If so, could you please provide a list of recommended supplements?

So you have established that both you and your 'physician' don't know what the problem is, but you have decided to treat parasites... hmmmm

I think you should read books about raw foods and what kind of mess happens inside people's bodies from incorrect living habits. Then pick a way of cleaning up the mess that you can handle over a long term.

I would sincerely appreciate your response.

Pick 4 different diets and try them each for 1 week and then stick with the best one.

Find a proper shaman to help you with these problems and pay them some money.

This parazapster dude below maybe he is a smart guy, maybe not, but this post about magnesium is beyond comprehension.

You need a complete overhaul of your life. Aside from that just stick with what you are doing and enjoy yourself.