re = /<span id=pink>.*?<\/span>(.*?)(?=<span|$)/
str = '<span id=pink>some short text</span>
more text that can be a few lines
<span id=pink>again a short text</span>
More text that\'s abiding the same logic
<span id=pink>Repeat</span>...(more of these)'
subst = ''
result = str.gsub(re, subst)
# Print the result of the substitution
puts result
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html