Inclusion Criteria

INCLUSION CRITERIA:

- Patients ≥ 3 and < 21 years of age at the time of study registration.

- Patients newly diagnosed with Wilm's tumor and scheduled to receive at least 9
consecutive weeks of chemotherapy with a vincristine-containing regimen.

- Patients newly diagnosed with rhabdomyosarcoma and scheduled to receive at least 9
consecutive weeks of chemotherapy with a vincristine-containing regimen.

- Patients newly diagnosed with ALL and scheduled to receive 4 consecutive weeks of
chemotherapy with a vincristine-containing regimen with accompanying steroid therapy.

- Patients newly diagnosed with NHL and scheduled to receive 4 consecutive weeks of
chemotherapy with a vincristine-containing regimen with accompanying steroid therapy.

- Patients with no underlying neuromuscular disease or peripheral neuropathy

EXCLUSION CRITERIA:

- Abnormal baseline peripheral neurologic exam (i.e. or peripheral neuropathy)

- Patients with:

- seizure disorders

- primary intracranial malignancy

- family history of Charcot Marie Tooth Disease

- a recent history of GuillianBarré26

- Patients receiving concomitant itraconazole are at risk for increased vincristine
toxicity and therefore are ineligible.

- Patients who are regularly using laxatives or stool softeners for constipation at the
time of enrollment are not eligible to participate in the study. Likewise, since
prevention of neuro-constipation will be evaluated, patients with an ongoing history
of constipation that has required frequent use of laxatives or stool softeners should
not be enrolled.

- Patients should not be scheduled to receive laxatives or stool softeners
prophylactically to prevent constipation, as the prevention of neuro-constipation
will be evaluated in this study; however, when patients show signs of developing
constipation while on chemotherapy, as determined by the treating physician, they may
be treated with laxatives or stool softeners at the clinician's discretion. Use of
laxatives or stool softeners will be documented on the concomitant medication log.