Only about 50 hours passed between when I first felt the tell-tale signs of a bowel obstruction and when the obstruction had been resolved in a 45-minute laparoscopic procedure. With nothing to eat or drink, and an NG tube relieving pressure during most of that period, it’s hard to imagine that whatever insult my bowels received would have been enough to send me into a month of post-operative discomfort, but that’s what happened.

My four day hospital stay included one dose of the antibiotic Ancef (cefazolin), commonly prescribed as a surgical prophylaxis, and a single intravenous course of pepsid, which I took late at night after surgery when I felt my bowels might be pushing the wrong way. That’s it.

From late Tuesday night, till my hospital admission and NG insertion on Wednesday evening, to the laparoscopy on Friday, to discharge on Sunday morning, my body of course sustained some shock but it hardly seems appropriate to the severe discomfort I felt in the the following weeks.

Upon arrival home, I followed the standard discharge advice about eating soft foods until my bowel movements returned, and that’s what I did: a whole milk latte, bananas, yogurt, ginger squash soup, some rice porridge. I was able to go for long walks, up hills, and I even contemplated a bike ride but didn’t want to push myself too much. At first I didn’t feel like eating too much, but by Wednesday I was getting hungry enough that for dinner I ate a large bowl of rice with curry chicken, followed by a pudding desert. Although I felt discomfort, some gurgling and bloating, it didn’t seem unusual in light of the ordeal I’d experienced.

By Thursday I was much more concerned about constipation. The initial day or two of near-diarrhea, I assumed, might have “cleared me out” and explained my lack of bowel movements, but after three days I was starting to feel genuinely uncomfortable. I remembered that the discharge instructions included a recommendation for the stool softener docusate sodium, so I bought some and waited for relief. Whether thanks to that or not, the constipation ended a day or two later but I then I felt something much worse: serious bloating and distention, enough to make me not want to eat.

By Sunday, a week after my discharge, I felt like my condition had clearly regressed. I no longer could go on neighborhood walks without discomfort, and despite my disinterest in eating, I was clearly hungry and losing weight. Waking up I felt fine, but the bloating seemed to increase throughout the day until it was difficult by bedtime to swing myself onto the bed without pain.

At this point, I now realize, I should have immediately changed my diet. I was eating classic FODMAP-heavy foods, like bread and dairy. But I continued to double-down, drinking high-sugar, high-calorie Ensure drinks and whey protein smoothies hoping to get enough calories. I assumed that my problem was motility, and that the constant wrenching of my gut was a sign that the muscles hadn’t learned yet which direction to push. But I now know that the real issue was gas, probably methane or hydrogen generated from bacteria that were too high in my small intestine — classic signs of Small Intestinal Bacterial Overgrowth.

I was desperate enough now that I wanted some medical advice, and the hospital switchboard promptly assigned me a physician who, upon hearing my continued symptoms, assumed my problem was another obstruction and recommended I come in for more imaging. Another doctor friend, who deals with bowel obstructions regularly, suggested my problem might be lack of movement. Whatever you do, don’t lay down — move, move move! he suggested.

The best advice seemed to involve simply not eating. I gave up all food except clear liquids and felt much better, which of course is not sustainable. Such a low calorie diet, coming up now on two weeks, essentially amounted to an unplanned fasting regimen, so at this point I began to take regular ketone measurements and found, sure enough, that my body is in a state of ketosis.

The following week was especially bad. Here, a full two and then three weeks after the surgery I was feeling seriously lethargic (lack of food) and unable to eat more than a few bites without painful bloating and abdominal pains. The only foods that seemed to offer relief were bone broth and a FAST bar — the specially-formulated high-calorie nut bar recommended during a fasting mimicking diet.

The condition became especially bad one night, after a large lunch and then dinner with a burger and bun, I was unable to sleep until at 12:30am I got out of bed with bloating so severe I seriously considered calling the emergency room again. I assumed I was simply obstructed, and that I might need an NG tube insertion and perhaps further surgery, but after somehow falling asleep, I thankfully woke in the morning feeling much better. The regular BMs I experienced also made skeptical that the problem is an obstruction.

So what else could it be? I contacted my naturopathic doctor

Recovery is taking longer than I’d hoped. Although I’m having regular BMs, I still suffer lots of gurgling noises and it’s very hard to eat enough calories without feeling bloated. Rarely get above 1500 calories/day, though so far I’ve only lost about 5 pounds. Mornings I’m registering ketones about 0.8 mmol/L. Solid food is especially hard, so instead I’m downing as much Ensure and other high-cal smoothies as I can tolerate. Otherwise no other complications — I’m able to go on long walks, sleeping well, etc. I guess it just takes time.

When a week later — three full weeks after my surgery — I was still in pain, I spoke with my surgeon who suggested the problem might be SIBO: small intestine bacterial overgrowth. This is a not-uncommon side effect of a bowel obstruction, when enough food gets stuck too high in the digestive tract, enabling colonies of bacteria to proliferate, digesting and fermenting food too early in the digestive process. Once gaining a foothold, these bacteria can be tough to eradicate, since their position at the front of the food line means they have first dibs on anything that enters the alimentary canal.

The fermentation results in gaseous by-products, usually methane and hydrogen, that form gas bubbles, painfully expanding the intestinal lining and generating all the symptoms I felt: bloating, painful distention, loud gurgling noises as the bubbles and undigested food pass lower into the colon.

Commercial SIBO tests involve a challenge drink, usually a sugary solution that will super-charge the fermentation process and generate gases that can be detected from burping. You breath into a tube that is sent for mass spectographic or other analysis to confirm a high percentage of methane and / or hydrogen. This is not necessarily proof of SIBO, but together with other evidence it’s a good indicator.

When I found it would take several days to take the test and get results, I decided it was easier to simply jump to the treatment. The SIBO microbes need specific nutrients in order to generate the gases that cause the trouble, so the easiest solution is to simply take those nutrients out of the diet. Long-time research, much of it at Monash University in Australia, has identified a class of foods, identified by their chemical composition with the abbreviation FODMAP, which are known to exacerbate production of hydrogen and methane gas. Treatment begins with removal of high-FODMAP foods from the diet.

Sure enough, this diet brought me immediate relief. In my zeal to gain weight, I was unfortunately filling myself with high-calorie, often high-sugar foods, like dairy and carbohydrates that were the opposite of what I should have been eating. When instead I substituted low-FODMAP fats, like eggs, fatty meat, almond milk, coconut and others, I no longer felt any bloating. Within a day or two I was able to greatly increase my overall caloric intake to my daily required level and then beyond.

The low-FODMAP diet was easy for me, mostly involving the elimination of all dairy and wheat along with a few common spices like onions and garlic. Instead, I was welcome to eat as much as I like of eggs, walnuts, peanut butter, and carbohydrates like quinoa and potatoes. With a few notable exceptions like avocado, most of the allowed foods are keto-friendly, which these days are easy to find on food labels.

Although in my case it was easy to eliminate the short-term symptoms, SIBO is notoriously difficult to treat in the long term. Most patients find quick relief on a low-FODMAP diet, but only because this eliminates the annoying gas buildup that causes the bloating and abdominal pain. SIBO microbes don’t disappear; they continue to eat as before, only without the gaseous side effects. Important nutrients are digested too early, so sufferers can find themselves deficient in iron or vitamin B12. Fiber can exacerbate SIBO symptoms, and long-term avoidance will generate other problems.

Serious SIBO cases can sometimes cause years of trouble, and patients go back and forth among different diets, often taking a round of the mild antibiotic rifaximin, preferred because it doesn’t seem to dissipate into other bodily tissues and inadvertently disturb the rest of the microbiome. I’ve met people who suffer for years from this condition, sometimes combined with IBS or other gut conditions that result in untold suffering and years missing out on the pleasures of food.

My doctors suggested I stay on the low-FODMAP diet for several weeks, perhaps a month or so before slowly reintroducing some of the forbidden foods, but in my case I felt so much better so quickly that I began “cheating” after the first week. When I saw virtually no problems from eating a little avocado, then banana, and finally beans and even dairy, it was clear that whatever originally caused my suffering was no longer there.

Now, five weeks after the initial obstruction, I’m back to eating exactly the same omnivorous diet I’ve enjoyed for years and I feel no discomfort whatsoever. The dramatic improvement I felt immediately, plus the speedy and apparently complete recovery make me wonder if in fact maybe it wasn’t SIBO at all.

Is it possible that the antibiotic I took during surgery wasn’t the real cause? Maybe it was the small hospital dose of pepcid, ostensibly taken to help some of my initial symptoms of what seemed like heartburn, maybe that changed the acidity of my stomach enough to enable some of the SIBO-causing microbes to gain just enough foodhold to cause me discomfort at the beginning when they were well-fed, but that a few days’ starving them of lactose and gluten maybe was enough to let other microbes outcompete them, my stomach to return to its normal acidity, and finally my regained peristalsis to clean out the upper intestines and send me back to normal.

Bottom line: I don’t think my case will be helpful to others who are suffering from “real” SIBO, one caused by a severe long-term challenge to the microbiome, as with a chronic condition like Crohn’s or IBS. Still, the next time I’m in a situation where I need to be more careful about diet – such as after recovering from an illness, or God forbid, another bowel obstruction – I’ll switch to the FODMAP diet by default, rather than wait till symptoms become undeniable. In fact, the diet is easy enough at the beginning that I suggest anyone consider it right after a hospital discharge. I wish I had done that.