I would make sure that you had enough digestive enzymes to begin with. I had very slow transit time in my intestines, but taking enough digestive enzymes (or apple cider vinegar, which also helps to detox!!) has made a major difference for me.
The other thing is that you could be experiencing psuedo-blockages if your intestines stop working for longer periods of time (days). Healing these infections *should* heal your digestive issues.
And actually, online it says that domperidone is an over the counter item.
Do be sure that you are using enough magnesium as well. I actually use two different types - one for my body and one to help out my bowels. Magnesium oxide, while it has poor availability for the body's general needs, it pulls in extra water into the colon - which can really help a lot of people suffering from constipation.
www.globalhealingcenter.com/natural-health/types-of-magnesium/ The best way to find the dose YOU need, is to find your bowel tolerance. Start out with a small amount and very gradually increase it at your own pace, gradually taking a little more each day. If at any time along the way, you get abdominal discomfort: a rumbling stomach, excessive gas, or diarrhea, go back to the amount you reached before you encountered problems.
Be sure you drink plenty of water - the amount I have found I need is around 64 ounces a day, more during the hotter summer days and I can get away with a bit less some winter days.
And never, ever "hold it". Go when you have to go, you are training those muscles and your body to get rid of the waste and toxins as soon as it can. When I was still able to work, I didn't realize that by just 'holding it' would complicate my issues - oh if I could go back and undo that part at least!