The answer to this question would appear that YES the stomach can
explode after consumption of Bicarb of soda.
However in most cases this is fatal and the flaps at either side of
the stomach release the pressure before this occurs.
Shows papers written by academics in relation to this subject
"NM Downs, PA Stonebridge, Department of Surgery, Royal Infirmary,
Edinburgh. "Gastric rupture due to excessive sodium bicarbonate ingestion"
Scott. Med. J. 34(5) 534-5 (1989)
F Tonetti, P Gorini, "A case of stomach rupture after ingestion of sodium
bicarbonate" Minerva Chir. 43(20) 1737-9 (1988)
P Barna, "Sodium bicarbonate: burst stomachs and high sodium" J. Clin.
Gastroenterol. 8(6) 697-8 (1986)
N Lazebnik, A Iellin, M. Michowitz, "Spontaneous rupture of the normal
stomach after sodium bicarbonate ingestion" J. Clin. Gastroenterol. 8(4)
B Brismar, A Strandberg, B Wiklund, "Stomach rupture following ingestion of
sodium bicarbonate" Acta Chir. Scand. Suppl. 530 97-9 (1986)
A case of stomach rupture occurring after hyperdistention of the stomach
following ingestion of sodium bicarbonate is described and the
pathophysiological mechanism is discussed."
The human stomach can hold 50 and a half Nathan's hotdogs (which is quite a few!)
This website shows a good discussion about this happening
It mentions that at least 5 or 6 documented cases have happened over
the past 60 years.
This site leads to some interesting reading, especially the last section
"Only one animal study was found to address baking soda's chronic
toxicity: a three percent diet of baking soda fed to rabbits resulted
in reduction of weight gain and may promote cancer. Baking soda, on
the whole, is of comparatively low concern for acute poisoning. The
most significant concerns are for household poisonings through
ingestion. The use of baking soda as an antacid has caused incidents
of stomach rupture when large doses are ingested."
The short answer is yes your stomach can rupture after consuming high
amounts of baking soda, however this only generally seems to happen if
either 1 of these conditions occur.
1 The subject has a weakened stomach lining (through ulcer or some
other medical problem).
2 The openings at both ends of the stomach fail to release the
pressure build up causing the stomach to rupture.
Explosion is not the term that can be used here but a breach of the
stomach lining can be applicable.