Good news: even without an appendix, your gut still recovers completely after massive diarrhea, antibiotics, etc. Your gut has other reservoirs for good bacteria.

The case against appendectomies is weak, but growing. We know the appendix does good stuff, but that good stuff is small and is significantly outweighed by risk.

Background: appendicitis is inflammation in one of your internal organs, usually resulting in catastrophic failure. The appendix is like a fragile balloon, the inflammation easily causes it to rupture, spilling bacteria and infection into your internal body cavity.

Pre-surgical intervention in ~1800 and something, it was close to 100% death.

Modern practice: three methods of treatment. (1) do nothing, observe, (2) strong dose of antibiotics, (3) surgical removal.

The timing for (2) is difficult and the consequences of failure are bad. There is a risk/reward calculation. Step (2) you avoid surgery, which has some small potential of things going wrong. But if it escalates, you are now starting stage (3) anyway but with slightly higher risk than earlier in the day. Roughly, 40% of antibiotic treatments need to progress to surgery. 10% of early patients have complications such as perforation (e.g. burst appendix, long recovery, more drugs), but 30% of late patients develop complications. If surgical resources are available, let's just do that now rather than let it get worse.

We evaluate all risks. Risk of early surgery, risk of later surgery, availability of resources, immediate and long term life style risks.

We know appendectomy changes your gut microbiome. Not necessarily worse, just different.

For instance, regular population about 35 people in 100,000 develop colo-rectal cancer. After an appendix, that goes up to ~70 in 100,000. Note: still a 99.9+% nobody develops that type of cancer.