Hmmm...Benadryl helps...that is a good clue. Benadryl is an anti-histamine drug. One of the things that histamine does in the body is all that itching and allergy stuff. The other (and relevant) thing is that it triggers stomach acid to be produced. So Benadryl might be preventing that histamine from being released in your stomach and preventing exces acid.
Drugs that are more specific to the histamine receptors (type 2) in the stomach are things like Pepcid, Zantac, Tagamat and others whose generic names end in -tidine. You can try them for relief and they should do better than Benadryl (try to stay away from Tagamet,especially if you take other medications...it interacts with them and screws up the dose your body is exposed to).
I think the other thread about Stomachs Not Hurting Anymore by Mr. Marsh advocated drugs like Prilosec, Prevacid, Protonix, Nexium and Aciphex. These drugs are called Proton Pump Inhibitors and work at stopping the actual pumps that throw protons into your stomach and make it more acidic, thereby reducing the acidity. These drugs are becoming more favored as time goes on as they demonstrate a more superior acid suppression than the Pepcids and the Tagamets. Currently, only Prilosec is available over the counter and is worth the try, but do not expect immediate relief from it, as it does take time for it to work. These should really be reserved in the chronic acid conditions that occur frequently (like daily or every other day).
For immediate relief, the good ol' Maalox and Mylanta are the fastest out there as they neutralize the acid the fastest. But they should not be taken on a long term basis, as your body can begin to accumulate metals such as aluminium in your body (nobody wants to have tin foil coating their kidneys). The Pepcids and Zantacs work in a few hours and can be taken daily for relief, but for real long term therapy, the Prilosecs and the Prevacids are more favored for their superior relief.
Non drug therapies include avoidance of foods that trigger the acid, such as alcohol, chocolate spicy and oily/greasy foods (so basically, mow your lawn and eat the grass clippings). If night time symptoms occur, you can actually raise the front part of the bed with blocks under the feet so that your head is slightly higher than your feet. Gravity will keep the acid down more. Exercise and losing weight when overweight can help, as well as eating regular healthy meals with about 2-3 hours of separation between a meal and lying down. lying down immediately after a meal is a big no-no too.
However, if this is a real that occurs on a regular (daily or every other day basis), do see a doctor and let him/her know of it so they may do a more comprehensive evaluation and rule out other possible causes. If you are an adventurer, try out the Prilosec for 2 weeks (like Mr. Marsh said) and you should notice a difference.
Best of health.
