 This phase III trial studies the side effects of genetic analysis-guided dosing of paclitaxel albumin-stabilized nanoparticle formulation, fluorouracil, leucovorin calcium, and irinotecan hydrochloride FOLFIRABRAX in treating patients with gastrointestinal cancer that has spread to other parts of the body and usually cannot be cured or controlled with treatment. Drugs used in chemotherapy, such as paclitaxel albumin-stabilized nanoparticle formulation, fluorouracil, leucovorin calcium, and irinotecan hydrochloride, work in different ways to stop the growth of tumor cells, either by killing the cells, by stopping them from dividing, or by stopping them from spreading. Genetic analysis may help doctors determine what dose of irinotecan hydrochloride patients can tolerate. 