You have really had a difficult time. I am glad you are looking for solutions. It always encourages me to meet an informed patient.
We do not consider it common or expected for a person with an ileal conduit to develop an infection. The symptoms of infection are increased amount of mucus in the urine, cloudy and strong smelling urine, fever, flank or back pain, nausea and vomiting or blood in the urine. There is an increased risk of urinary infection with an ileal conduit is because an ileal conduit is a tube made out of ileum or small intestine. One end of the tube is fashioned into a stoma or opening at the skin. The other end of the tube is closed and the ureters from the kidneys are sewn to the tube. This creates a situation where the urine may back up or reflux up into the ureters which can cause a urinary or Kidney infection.
I did some digging at www.c3life.com or www.ostomy.org and other sources. It is estimated that one in ten people with ileal conduits will have an infection. It was suggested it may be possible for your surgeon to have a radiologic test like intravenous pyelogram to determine if urine is pooling in the conduit and backing or refluxing up the ureters. This can happen if the conduit is long or if the site the ureters and conduit are sewn together (uretero-conduit anastomosis) is not optimal.
Your other questions are easy for me to answer.
1) Drink plenty of fluids - 2 to 2.5 liters a day. Being well hydrated with flush the ureters, dilutes the bacteria and promotes the acidic environment to help prevent growth of bacteria.
Wash your hands before and after caring for your urostomy. Use a pouch with an anti-reflux valve. Anti-reflux valve is an internal flap in the pouch that keeps the urine from collecting around the stoma. Empty the pouch when it is 1/3 full . When sleeping, connect to a bedside drainage container so the urine can't pool around the stoma. Drinking 8 - 10 oz of cranberry juice a day (if this is does not interact with any medicine you are taking) which can help acidify your urine.
2) Change your pouch every 3-4 days if you are having problems with infection. If not, the pouch maybe worn up to 7 days just look at the barrier or sticky material around the stoma. If it is wearing away exposing your skin or becoming mushy near the outer edge of the wafer, it is time to change the pouch. We recommend wearing an urostomy pouch with an extended wear barrier.
3) Empty the pouch when it is 1/3 full and connect to a bedside drainage container while sleeping .
4) The white ring around the stoma is not the cause of the UTIs. It is how the barrier or sticky material around the stoma was designed. The material sometimes called a hydrocolloid absorbs moisture and swells to make a better seal around your stoma. It is suggested that infected urine will wear away the barrier faster. Maybe due to the more basic pH of the urine.
An extended wear barrier is more resistant to urine and will not become mushy quite as fast as a standard wear barrier. Each manufacturer has a different name for their extended wear barrier.