The topic at hand is about finding a reliable ostomy system that prevents leaks, especially when the output exits at the base of the stoma. This can be a tricky situation, as the output is almost level with the skin, making it challenging to find a system that works effectively without causing discomfort or noticeable bulging. Here are some insights and advice shared by others who have faced similar challenges:

- The current convex system being used is the Salts Convex, which provides the necessary projection but still leaks during activities like running for a bus. It also causes the stoma to bulge noticeably.

- Flat systems from brands like Salts, Coloplast, Pelican, and Hollister were tried, but they all leaked, although they did eliminate the bulge.

- The situation is complicated by a surgical scar on the left side, which requires a barrier ring. Convexity helps lift the stoma away from the scar but also pushes it outward.

- The Pelican Convex system has provided the best seal so far, but the bulge it causes is not acceptable.

- Only one-piece bags have been used so far, but there is now consideration of trying two-piece options.

Questions raised include:
1. Does anyone else have a "bottom-exit" stoma, and which products work for them?
2. Does the size or shape of your stoma change between flat and convex systems?
3. Does switching to a two-piece system help with a low-exit stoma?

Advice and insights from others include:

1. Surgical revision suggestions:
- Consulting with a surgeon is advised, as a stoma should ideally protrude about 1 inch. A revision could correct a flush or downward-pointing stoma and potentially solve chronic leaks.

2. Hollister 2-piece convex setups:
- The Hollister New Image Convex wafer combined with a drainable pouch, such as wafer #14604 with pouch #18194, or other Hollister 2-piece convex models used with a moldable or standard barrier ring, can provide a secure seal for liquid output. These systems can be "burped" for gas, and wear time is reported to range from every other day up to 2–3 weeks without leaks.
- Tips include cutting the wafer opening about 1 mm larger than the stoma and fitting the ring snugly. Routine changes twice weekly can help maintain skin health.

3. ConvaTec option:
- The ConvaTec ActiveLife 1-Piece Drainable Pouch #5122771 is praised for its comfort and minimal bulk. Users change it every other day to prevent seepage and skin irritation.

4. General fitting tips:
- Always pair convexity with an appropriate seal or ring to fill uneven skin, including surgical scars.
- Frequent changes, every 1–2 days, can reduce the risk of undermining leaks for high-volume or liquid output.
- Two-piece systems allow for pouch swaps without disturbing the wafer, which some find reduces leaks and skin trauma.
- If leaks persist even with the correct products and technique, revisiting stoma construction with a surgeon remains a viable long-term solution.