Best adult diapers/pads for post prostate surgery

A couple of things:
1. Start doing Kegel, "pelvic floor" exercises "before" the surgery. It will give your husband a little head start.
2. Diapers or pads? It is dependent on what type of underwear he normally wears. "Pads" to do not work in boxer shorts...they will fall out, especially when they begin getting heavier with collected urine. Pads work best with jockey undershorts. Diapers work best with boxers.
3. Don't make the mistake that I did: When I was back out in the world after my catheter was removed at the 11th day post-surgery, I was leaking pretty badly, so I thought that I'd be "smart" (nope) and put a Depends "pad" inside my Depends "diaper" and slip my boxer shorts over that, plus my casual attire shorts. I needed an easy way to slip into a bathroom, pull out the soaked wet pad, and replace it with a fresh one that I carried in my pocket. Here was the accidental epiphany moment: I was out on errands quite a while. I used my back up pad, and it too got soaked during the next hour that I was out on errands. I couldn't stand the wet, uncomfortable feeling of that soaked pad, so I pulled it out in the restroom, and wore just the diaper until I got home an hour later. I immediately noticed that I stopped leaking without the pad in my diaper! The "epiphany" moment was that I realized that the thick pad really was "too much" down there...it occupied too much space within the diaper, and it pressed up on my perineum and therefore pressed against my bladder, causing the very (excessive) leakage that I was trying to avoid. From that day on, I stopped wearing a pad inside my diaper. Life has been great. I can go many hours (2-3 diapers a day, so one diaper slightly wet every 8-12 hours) with very little leakage now. Part of this success is also due to the next factor:
4. Make sure you husband's urologist writes an order for Pelvic Floor Physical Therapy (PFPT). It is a subspecialty for physical therapy, mostly for postpartum women to regain their continence, but many post-RP men go as well to get that extra help with Kegel's and many other exercises that strengthen the pelvic floor. There are some pretty wild exercises beyond Kegel's that help.
I read in Dr. Patrick Walsh's book: "Surviving Prostate Cancer" (the "bible" for men with this issue), that we have three sphincters between the bladder and the tip of the penis (there is not one at the tip though). The nature of RP surgery, is that two of the three sphincters that control retention and control of urine and urination, are removed with the prostate. The "one" sphincter that remains, is the weakest of the three, so it really needs to be re-trained to help retain urine and stop leakage. I read a statistic that roughly 2/3 (66%) of men regain most/all of their continence within the first 90 days post-RP. I can say that I am not perfect yet, but I am 95% there at four months post-RP. I still have my accidents..what is called "stress incontinence"...doing every day little things like standing up, or sitting down (especially in my car), and sometimes spontaneously while walking. I just make sure that I urinate before I leave the house, and that I am really empty before leaving. I usually urinate, then do a couple more quick things for five minutes, then urinate one more time. There is always another 5 - 15 ml that somehow comes out, even though I thought I had emptied my bladder minutes before. My PFPT even says that when home, I should "sit down" to urinate. It is better/easier on the pelvic floor muscles and helps you really get every drop out. I usually forget to do that half of the time, but I am trying to do better. It is just a weird thing to do as a man...men stand, women sit. It is weird, but I try to sit. Part of PFPT also includes a close examination of when and how much liquid you drink. I am on a strict, modified liquid consumption schedule: no caffeine, no carbonated soda's/beer, no acidic drinks like my favorite OJ, and only 8 oz (1 cup) of "water" at any given time. I am to "time" consumption of that 8 oz with urination, and I am to urinate every two hours whether I feel like I need to or not. That all has really got me under better control. I break the rules and take little sips of my favorite decaf sodas just to get "flavor" in my mouth (drinking water 100% of the time is impossible for me, and likely everyone else). But all of that actually helps. Your post-surgical bladder gets angry...pissed off (pun intended)...with caffeine, carbonation, and acidity, and will cause you to leak. The bladder is irritated with those things, so water is the preferred drink each time you drink that next 8 oz. I just find drinking water all day, every day, nearly impossible and boring.
I hope this helps the overall pre-surgical situation, as well as the post-surgical expectations and tips/tricks to have a minimum of frustration with leakage. Good luck.

Babies wear diapers. Adults wear incontinence underwear and pads. We lose enough dignity through this process. My answer is which ever fit the best.

All of the comments here are excellent and come from experience (unfortunately!). So let me add mine: Do NOT go to bed without a full diaper for a few months post surgically; it doesn’t matter how continent or leak free you are during the day. Nighttime is primetime for major accidents!
Had to throw out hundreds of dollars worth of mattress pads, mattress covers, etc. before I realized that these episodes had nothing to do with too many fluids after 8PM, club soda or anything like that.
A simple passage of gas, while asleep, could open the floodgates (sphincter) to a soaking wet bed; as could a rapid change in sleeping position, a cough or a sneeze…
Just put the diaper on and you’ll have no anxiety for the rest of the night. Best,
Phil

Sorry to hear that. Sleeping at night has been my only relief...it is a "gravity thing" I think: laying flat removes any/all pressure on my bladder, so no leaks.
From the first day/night after my catheter was removed, I was able to sleep through the night, or...actually, after the first month or so, before I started Pelvic Floor Physical Therapy (PFPT), I was getting up in the middle of the night at about 4:30 - 5:00 a.m. to empty my bladder, until post-surgical recovery aided by the PFPT brought that under control.
I was in health care for 40 years and never learned that as we age, our bladders get smaller. That was in fact my first motivation to get a PSA test done after four years (Yep...foolish of me): In September of 2024 at age 69, I suddenly was having to get up anywhere from 2:00 - 5:00 a.m. to urinate. That had never happened to me before. The urgency/necessity awakened me. I was NOT happy...I hate being awakened for any reason. So, I realized it had been four years since my general practitioner had quietly closed down his practice without telling his patients (ya...a real jerk...no notice to us whatsoever). Because I am Diabetic and otherwise have always been very healthy, I suddenly had let four years slip away. The awakening at night to urinate motivated me find a new Internist, and to get a PSA = 6.1 ng/ml. And thus started the rapid sequence to biopsy, PET Scan, DaVinci Robotic-Assisted RP, and an unexpected/unfavorable outcome based on the pathology report vs the biopsy report: 3+4 = 7 Gleason. Per the biopsy report, my urologist was confident that "we caught it early, you'll be alive in 15 or more years", to the surgical pathology report - EPE, surgical margins, cribriform glands, and left seminal vesicle invasion, making me a pT3b with the near "guarantee" that my cancer will return within the next 5 years, especially with my urologist leaving behind some cancerous prostate tissue (part of "surgical margins"). I am one of the unlucky 10-20% where there are "surgical margins." So...
Your nighttime leaks (or floods) will come under your control in due time. Hang in there. Try to get into the practice or habit of what my PFPT therapist has me doing: Urinate every two hours whether you need to (feel it) or not. And drink one cup of water (8 oz) only before or after you urinate. If you are of normal height and weight for a man, per my PFPT I should be drinking about 48 oz of water every day, possibly as little as 40, and as much as 54 oz. Avoid/eliminate caffeine, alcohol, carbonation, and acidic drinks (Orange juice). All of those are bladder irritants that will make your bladder angry and overactive to urinate. Good luck.