\tikzset{
  process/.style={
    rectangle,
    minimum width=2.5cm, minimum height=1cm,
    draw,
    text centered
  },
  % Decision (diamond)
  decision/.style={
    diamond, aspect=2,
    minimum width=2.5cm, minimum height=1cm,
    draw,
    text centered
  },
  % Arrow style
  arrow/.style={
    thick, ->, >=Stealth
  }
}

\begin{tikzpicture}
  \node (start) {};
  \node[decision, below=of start] (decision) {\textbf{\textcolor{magenta}{Bedingung}}};
  \node[process, below=of decision] (process) {\textbf{\textcolor{orange}{Anweisungen}}};
  \node[below=1.2cm of process] (end) {};

  % Arrows
  \draw[arrow] (start) -- (decision);
  \draw[arrow] (decision) -- node[right] {Falsch} (process);

  % Decision branch
  \draw[arrow] (decision) -- node[above] {Wahr} ($(decision.east) + (1cm, 0)$) -- ($(decision.east) + (1cm, -3.4cm)$) |- ($(process) - (0, 1.1cm)$);
  \draw[arrow] (process) -- (end);
\end{tikzpicture}