Too bad you did not say to him « sorry but I do not really understand what you are telling me would you mind to elaborate » may be next time you see him.. I can only assume that through years if being constipated you had to strain which damaged your colon which is why you are having problems especially if you have IBS on top. The diarrhea could be un-related caused by a bacterial infection.
Sometimes a barium enema helps but if you have a bug you might need antibiotics. Make sure they do not give you a dose to kill a horse which they often do.. at your weight it could damage you further plus you are already weak & the antibiotics side effects can be devastating! Stay away from Cipro & Amox. You do not need C-diff on top of your problems. May be you should see a Nutritionist who might help you to re-balance your intestinal flora. Good luck I truly sympathise with you having similar problems.

Please see another gastroenterologist at a highly rated facility ASAP for another opinion. Tell them this is urgent and you need an appointment promptly. Have complete results if your previous tests and procedures sent to them before your appointment. Your condition sounds much too serious and complex to be waiting for input (even well meaning) from this forum or another round with your current doctor. Best of luck to you.

We live in a very small rural area that doesn't really have any high rated facilities. I don't know if my insurance would let me switch Dr.s/facilities or not? I could check. But he didn't say anything about this being an urgent or serious matter. He just said he could only get the scope a tiny way into my colon because it was "like a colon of an 80 yr old". I just don't know what he means by that. I know he wants to see all my colon to make sure there's no cancer but a barium enema only shows the very lower portion of the colon anyway from what I have read. I'm not even sure any of this is necessary? I realize colonostomys are important, but I don't want to go through 2 days w/o eating at my unhealthy weight loss and go through being awake through a very uncomfortable procedure if there is no reason for it. I don't know what to think or do.

@meningone - I agree with @jackiem95 You should see a gastroenterologist at a major hospital or university hospital where they see many more patients with complicated intestinal illness than in a smaller town. I understand it will be difficult to get to such a hospital, but this might be the time you have to do that. Most insurances cover second opinions. There are other ways to examine your colon, such as capsule colonoscopy. I had that once. You swallow a capsule with a tiny camera that can see inside the colon. However, doctors at these major hospitals also have more experience performing difficult colonoscopies. You need a diagnosis now.

@meningone - I understand that this new GI problem is overwhelming. I don’t mean to push you to make decisions- I just get passionate! All of us here in this group have gone through many different ordeals with our GI tract and like you have not always understood what’s happening.
I think I can try to explain what the doctor means by saying you have a colon of an 80 year old. You say that you have had severe constipation most of your life. When that happens the colon stretches more and more- like a pantyhose. It will also affect the ability to contract and move the stool forward. That is probably why the doctor talks about doing a colostomy- you would have a colostomy bag where the stool from small intestine empties. The colon would not have any function.
It would be good for you to have him or a nurse explain your problem in detail.
We are always here to listen!

Thank you all for your replies. I had to go to the town today where my colonoscopy ws performed. (An hour away & it's a small hospital, we don't have a hospital in my county). Anyway, I stopped by the Dr.'s office hoping he might be available. He wasn't but his nurse was. She said he was able to get part way up my colon but couldn't get around the loop at the top because it was so stretched. She explained I had severe diverticulosis. That it's a common condition but the advancement of mine is usually only seen in the elderly, typically around 80 yrs old. There were lots of inflammed protruding pockets. He just wants to be able to see my whole colon to be sure there are no other problems. So, that's the better explination I received. And I spelled colonoscopy wrong in an earlier paragraph. I said colostomy and didn't mean to. No, he doesn't want o do that. As far as we know there's nothing serious wrong with me. Just can't complete the procedure and I couldn't understand why. As for the pain, I've always had it and as far as I know there's nothing that can be done for it. I've just learned to live with it. It comes and goes to a certain extent.

@meningone is it possible that the recent diarrhea could be from something you are eating? I suddenly started having diarrhea almost daily after I started a new medication. I thought the diarrhea was strictly from the medication but after quite a while I started to notice that it was worse when I had foods containing lactose - it took me about two years to add this up! I stopped eating those foods and the constipation went away! I still think the medication had some involvement in my case, that it triggered the lactose intolerance but I have read that as people age many, maybe even most, develop lactose intolerance. It’s just a thought, but could be worth eliminating those foods to check on that. I had been having yogurt most mornings, goat cheese on a salad for lunch, plus lactose in other foods.
JK

I have all your problems & I totally understand your situation. I had serious issues with diverticulitis Every time I had an attack I had to have a scan & go on antibiotics which almost killed me. i lost 25 pounds. So I had a colon resection. They removed the part of my colon which was the most diseased & re-attached it. I do not have a bag & I am doing quite well with the right diet which is why I suggested to you to see a Nutritionniste. You need fiber in your diet but just the right amount
When our colon gets inflamed can be because we react to certain food or even because of stress it causes scar tissue which means your colon can be narrowed in certain places; it is called a stricture or stenosis. Which is why your doctor cannot pass with a scope even a small pediatric scope (child scope) By the way my gastro wanted me to do a short colonoscopy (rectal only) to assess my situation & because my colon is narrowed like yours I got in trouble with the prep...it could not go down.. so I started to vomit it ended up with a partial blockage in agony at the ER! They had to in-tube me to get the prep out! A barium enema or hydro soluble enema where the put a contrast in your rectum & take pictures has helped me.
Try to avoid a full colonoscopy prep just eat very lightly 3 days prior the procedure & use 2 fleet enemas the 2 days prior your barium enema.
1 at night & 1 in the morning. Best of luck 🍀🍀🍀 keep us posted.