There are several possibilities - belly bands, abdominal binders, and compression sports clothing.
Belly bands are available in Target or any store with a pregnancy section. They provide medium support to the abdominal area. Even though these are made for women, they will easily fit a man (think of a woman's pregnant belly!). Here is an example:
https://www.target.com/p/post-pregnancy-belly-wrap-belly-bandit-basics-by-belly-bandit-nude/-/A-54312604Abdominal binders are available on Amazon or medical supply sections of regular stores. They are more supportive, but vary widely in the area they cover. Some go further up the abdomen and some go down lower, so you need to read the details and see which one covers the pump area. Too much coverage feels uncomfortable. Here is an example;
https://www.amazon.com/dp/B015IUCF68/ref=sspa_dk_detail_2?psc=1&pd_rd_i=B015IUCF68&pd_rd_w=mYDfe&pf_rd_p=45a72588-80f7-4414-9851-786f6c16d42b&pd_rd_wg=ph6hz&pf_rd_r=A107H59WQQE7XMDJ4MDY&pd_rd_r=7d7ad137-c15e-431d-89ec-8aa4e30cd3e2&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUExUUVUSUxQMkMxSk5KJmVuY3J5cHRlZElkPUExMDA4OTM1UUw3NzBFTUw2ME1BJmVuY3J5cHRlZEFkSWQ9QTA0MzA5MjUyN0kwMUxTMFczVzdGJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==Then there are compression sports clothes - compression underwear, shorts, running tights, t-shirts, etc. These are great for hiding under your clothes and provide a high level of support for the HAI pump, an ileostomy bag, or just general support for a large incision after resection surgery. Plus they are the most comfortable of the choices. Here is an example of these.
https://www.nike.com/t/pro-mens-6-training-shorts-8lWbRN/838061-010I wear high-waisted running tights (like the ones below) to protect my pump from any movement when I'm doing physical activities.
https://www.nike.com/t/sculpt-womens-training-crops-KKmmj3/BV1364-010However, it's easier to find
high-waisted items in women's clothes than men's. He might have to look at compression t-shirts to cover that area if he's not interested in belly bands or medical binders.
I do recommend some kind of support though - it just feels more secure for the pump and it's more comfortable too!
Hope this helps!
Juliej