The first studies of exocrine pancreatic function in T1D were based on direct CCK and/or secretin stimulation and posterior measurement of enzyme content in duodenal juice [19]. The presence of pancreatic exocrine insufficiency (PEI) was demonstrated in 1943 by Pollard and colleagues [2], who reported a reduction in amylase and lipase after pancreozymin-secretin stimulation that was confirmed afterwards in multiple studies [20– 22]. These studies were, however, difficult due to the invasive nature of these test procedures, including tube application into the duodenum and continuous aspiration of duodenal secretion for several hours. Indirect tests became available afterwards and were based mainly on fecal chymotrypsin activity and fecal elastase 1 concentration (FEC) [23– 26]. Since these tests did not depend on specialized centers, it was possible to involve larger series of patients in clinical trials. The largest study was carried out as a multi-center trial in Germany, and the prevalence of exocrine pancreatic insufficiency was reported to be 51 % in patients with T1D and 35 % in patients with T2D [24]. The association between exocrine insufficiency and T1D is therefore long, affecting a large proportion of the patients, with an overall very variable prevalence of 43–80 % of PEI in patients with T1D [21, 27]. Recent studies have inversely correlated FEC to diabetes duration (not age) and HbA1c levels while it positively correlated to C-peptide and BMI [28]. It is now evident that exocrine function and morphology should be evaluated in patients with diabetes, at least at the time of diagnosis. Imaging techniques like ultrasound (US), computerized tomography (CT), and magnetic resonance imaging (MRI) can greatly facilitate the assessment of the pancreas and correlate volume with exocrine function [29–31].