Inclusion Criteria:

- Patient with GI neoplasm

- Patient that must start a (new) line of chemotherapy with at least 2 cycles

- Age > 18 ans

- Exclusively orally fed

- Life expectancy more than 3 months

- Intravenous 5FU-based chemotherapy with 2 or 3-week cycles

- Hematological toxicities from previous chemotherapies terminated or <= 2

Exclusion Criteria:

- Positive HIV status

- Pregnant or lactating woman

- Currently participating or having participated in another clinical trial during the
last month prior to the beginning of this study

- Patient having diarrhoea of grade > 1 for more than 2 weeks before the inclusion

- State of sub occlusion, chronic inflammatory diseases of the digestive tract,
radiation enteropathy

- Sepsis

- Concomitant radiotherapy, except analgesic radiotherapy