Systemic mastocytosis (SM) is a heterogeneous group of disorders caused by mast cell proliferation. SM often presents with non-specific symptoms making it a diagnostic challenge. Moreover, presentation with bone involvement is highly uncommon. Here, we report a rare case of SM in a 68-year-old female who initially presented with gastrointestinal symptoms and was later found to have sclerotic bone lesions on imaging. This case highlights an unusual presentation of SM, informing clinicians of the importance of keeping this disease process on the differential list of diagnostic conundrums.