The purpose of this study is to estimate the proportion of Ventricular Assist Device (VAD) patients with abnormal gastrointestinal bleeding as assessed by HemoQuant fecal occult blood test. Also, in patients with gastrointestinal bleeding present, to summarize the extent of gastrointestinal bleeding; to examine the behavior of HemoQuant fecal occult blood test over time by estimating the proportion of VAD patients with a positive test prior to implantation; at one week, one month, three months, six months and one year post implantation, and after explantation of the VAD and to evaluate whether presence of any abnormal fecal HemoQuant test is predictive of a future major bleeding event.

Inclusion Criteria:

• Group 1 - cross sectional study. Patients with implanted non-pulsatile ventricular assist devices of any type and at any time after implantation
• Group 2 - prospective study. Patients with usual VAD indications will be invited to participate, when, in the opinion of their treating physician a VAD will be highly likely within one month.

Exclusion Criteria:

• Unwillingness to provide stool samples for study
• Unwillingness to be followed for study endpoints.
• Unwillingness to follow dietary restrictions necessary for accurate HemaQuant measurement

• Group 1 Patients with implanted non-pulsatile ventricular assist devices of any type and at any time after implantation
• Group 2 Patients with usual VAD indications will be invited to participate, when, in the opinion of their treating physician a VAD will be highly likely within one month.