Transthyretin amyloidosis (ATTR) is a rare, progressive, life-threatening, hereditary disorder caused by mutations in the transthyretin gene. Due to the phenotypic heterogeneity, ATTR is difficult to recognize and it is often diagnosed very late. In ATTR gastrointestinal (GI) disorders play an important role in the patients' morbidity and mortality. In some cases, GI symptoms are present even before the onset of the peripheral polyneuropathy. However, the complaints are various and it is really difficult to differentiate them from other GI disorders. We present a 61-year old male referred for diarrhea, unintentional weight loss and early satiety. He had hypotension after longstanding hypertension, numbness and tingling in the feet. We considered a broad differential diagnosis spectrum of chronic diarrhea syndrome and performed numerous laboratory, biochemical, imaging, endoscopic, histological and genetic tests. Transthyretin amyloidosis with a Glu89Gln mutation was diagnosed. Transthyretin amyloidosis is frequently misdiagnosed, representing a diagnostic challenge in GI practice. The presence of certain clinical combinations could help gastroenterologists to include ATTR in their diagnostic work-up.