R ALA stand for R Alpha Lipoic Acid. Here is what it says on the first website I looked at:

R-Lipoic Acid Details
Alpha-lipoic acid occurs naturally as a 50/50 mixture of R-lipoic acid (R-ALA) and S-lipoic acid (S-ALA). R-lipoic acid by itself functions as an essential cofactor for many enzymes involved in energy production.* It also has characteristics, including significant antioxidant effects, that contribute to liver, brain, nerve, and eye health.* Studies indicate that supplements containing only R-lipoic acid appear to be better absorbed than supplements containing both R-lipoic acid and S-lipoic acid, with results showing twice as much ALA appearing in the bloodstream after an oral dose of R-Lipoic acid.* Because R-Lipoic acid is the form best utilized by the body, Thorne provides R-lipoic acid bound to sodium, providing it in its most stable, absorbable form.*

Alpha-lipoic acid, also known as thioctic acid, was discovered in 1951 as a molecule that assists in acyl-group transfer and as a coenzyme in the Krebs Cycle. In the 1980s, the scientific community realized that alpha-lipoic acid is also a powerful antioxidant.* What sets ALA apart from other fatty acids is that it's an antioxidant in both fat- and water-soluble environments, and it's also an antioxidant in both its oxidized and reduced forms.* This is unlike vitamin C, for instance, which is a water-soluble antioxidant, as well as vitamin E, which is a fat-soluble antioxidant. ALA also increases intracellular glutathione and CoQ10 levels.* Its other mechanisms of action include promoting normal protein glycosylation and inhibiting the enzyme aldose reductase, which in turn inhibits conversion of glucose to sorbitol.*

Hello @alglenn, Welcome to Mayo Clinic Connect. You ask a great question about the difference between ALA and R-ALA. The R-form of alpha-lipoic acid is the active, natural form. If you look closely at the ingredients for most ALA supplements you will find that they contain a large amount of S-ALA (synthetically manufactured and inactive form of ALA). Here are a few references that you might find helpful for learning more about ALA and R-ALA.

ConsumerLab.com - R-Form Alpha-Lipoic Acid & S-Form Alpha-Lipoic Acid:
-- https://www.consumerlab.com/answers/i-heard-the-s-form-of-alpha-lipoic-acid-is-bad-for-me-why-is-it-in-my-supplement/S-Alpha-Lipoic-Acid/
(R)-Lipoic Acid: Unique ‘Mitochondrial Antioxidant’ Fights Premature Aging:
-- https://nutritionreview.org/2019/07/r-lipoic-acid-unique-mitochondrial-antioxidant-fights-premature-aging/
Linus Pauling Institute » Micronutrient Information Center -- Lipoic Acid:
-- https://lpi.oregonstate.edu/mic/dietary-factors/lipoic-acid

Here is some information that I found on that may provide information to help.
Abdominal Wall Pain: Clinical Evaluation, Differential Diagnosis, and Treatment: https://www.aafp.org/afp/2018/1001/p429.html

There is also another discussion on Connect you may want to read through where other members are discussing similar symptoms.
Has anyone been diagnosed with Abdominal Wall Pain: https://connect.mayoclinic.org/discussion/has-anyone-been-diagnosed-with-abdominal-wall-pain/

You mentioned the abdominal pain - neuropathic/neuralgia. Did the doctors give you a specific diagnosis?