Sitting for rectal cancer patients: Any cushion suggestions?

Hi, @jmy75 !
Did your dad have a low anterior resection? Did he have radiation for rectal cancer?
Both of those procedures can affect the internal sphincter and make patients prone to fecal incontinence. There are solutions for it, depending on the gravity, the overall health of the patient, their age, etc. Your dad may be open to having pelvic floor therapy which is quite helpful in controlling fecal incontinence. The best kind of PFT includes biofeedback and neurostimulation. They may add PTNS (percutaneous neurostimulation of the posterior tibial nerve), which acts on the sacral plexus. Also PFT teaches you to breathe in the correct way for your pelvic floor.
There is also an implant that can be surgically placed to help control fecal incontenence. There has to be a careful analysis and a trial period, to make sure the patient is a good candidate for that solution.

I work as a translator and spend a lot of time seated. I use an ergonomic mesh chair. But the chair alone won't make enough difference to avoid accidents, I think.

Dad has had no surgery. Just the radiation. And I know that is what has caused it.

He will wear a maxi pad, diaper, 2 boxers and a pair of shorts under his jeans and still ruin the jeans.

It's just awful

In that case, I would insist on the pelvic floor therapy and talk to his doctor about a sacral implant.
Does you dad take any med like Lomotil or Imodium or does he use psyllium husk to bulk the stool?
Also watching the diet to balance insoluble and soluble fibers. After my surgery, I started with a very restricted diet, totally low fiber, and started adding one new food a week, or the same food differently (from cooked to raw, or from peeled to not peeled), so I could find out what would provoke gases, diarrhea or constipation. It can be helpful to consult with a clinical dietitian or nutriologist.

I give him lomitil, immodium, and the psyllium. Three times a day I give him fiber, immodium, and lomitil. He's not going to go through a sacral implant, he won't do any procedure, and I don't think he can get off the floor, he's 82. I've eliminated caffeine and artificial sweetners from his diet, I've tried hundreds of different things. I'm very tired.