What will happen to OTHER ORGANS if stomach malfunction due to certain disease?

it can start issues like cancer, lactose intolerance, heartburn , etc.

Explanation:

Problems with stomach emptying (gastroparesis) occur when stomach muscles don't work correctly. Although the underlying cause can't always be found, damage to pacemaker cells and nerves in the stomach due to diabetes or surgery can lead to stomach muscle dysfunction can also cause other issues like cancer, lactose intolerance, heartburn , etc.

Explanation:

stay safe

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.