Sensitive subject warning: Mother in law (83) refuses to make the effort to poop. Any advice?

I hope you are not the only one on the Poop Patrol. Is your H also (at least equally!) involved, since it is HIS mother?

We went through every combination of laxative and I scoured the internet for advice, it became almost an obsession because I spent so much worry and time mom's bowel movements. When mom eventually needed the NH I was afraid she would end up with a blockage because they seemed very blase about her bowel dysfunction but you know what, that never happened. They switched her to lactulose (probably the only thing we hadn't yet tried) and I gradually learned to stop asking about her bowels.

Constipation is a chronic issue when undergoing chemo. I found that staying ahead of the loop was the best. Still, sure had some miserable nights.

A 'squatty potty' was my friend, as also was belly massage. You can watch this online. It's very gentle and really helped.

I took Miralax in a little warm prune juice at night. Stool softeners also. Drank a lot of water and if it was warm, that helped stimulate the bowels.

Fiber Brownies are great. As my granddaughter warned me "One will make you happy, 2 will make you poop your pants". (she was 8 at the time, I still laugh at that when I buy those)

If she's feeling sick again then it's back to the doctor, I'm afraid. They should examine her thoroughly (i.e. not just stick her on an x-ray table), and this time perhaps they will also give her guidance about maintaining a good, comfortable, regular bowel habit, such as advice on diet and the use of mild laxatives.

She's comfortable on the loo, is she? It's the right height for her, so that she can rest her feet firmly on the floor, seat not too narrow and doesn't dig in to her bottom?

No haemorrhoids or anything like that?

My mom seemingly lost all sensation when it came to her bowels; she didn't know she had to go, she didn't know she had gone or was going, and she had no ability to push when she was seated on the toilet even when she was trying to comply for my sake. The best you can do is to keep her feces as soft as possible: lots of fluids, lots of fiber, probiotics and laxatives - for us regular use of miralax was a godsend. Keep a log of when she goes and be prepared to bring out the big guns (suppositories or fleet enemas) if it has been more than 4 or 5 days.

For my mother there is a fine line between not going and going too much. Mom was going but had hard stools and I didn't realize it was constipation until my RN sister made me feel guilty for making Mom suffer. As a result, I gave a capful of Miralax and 2 stool softeners daily and she ended up with the opposite problem - massive stool incontinence. For a while it was back and forth - either constipated or diarrhea but lately it seems that 1/2 cap of Miralax and 1 stool softener a day has been working well. She is still incontinent of stool and doesn't realize it, or sometimes she knows she has to go but not in time to make it to the bathroom. We have learned to listen for the bathroom door since we can't keep an eye on her all the time.

But I digress. I hope you find the right combination of supplements to help your Mom go. Good luck!

Pooping and not pooping doesn't usually come down to "trying" or "not trying". As food stays in the large intestine more and more fluid is removed from it and it is more and more difficult to pass from an aging and somewhat flaccid lower bowel. Rocking back and forth on the toilet seat may help. Fleets OIL enema WILL move out blockage, but it is a mess and the oil leaks out, and you will need depends or other incontinence wear while it is on board. A daily stool softener should be given. Also recommend citrucel which is much like metamucil but without the gas producing fermentation factors. It will bulk up and move stool more easily.
Remember, this isn't your Mom's fault. This happens with aging. There are ways to address it.
Wishing you good luck.